Elnätet dimensioneras för att klara årets största effekttoppar. Det är viktigt att överväga sammanlagringen mellan flera kunder, eftersom individuella kunders effekttoppar skulle ge felaktiga uppskattningar av nätstationens högsta förbrukning. Idag finns det timinformation om varje nätstations förbrukning, vilket inte fanns tidigare. Tidigare uppskattades storleken på effekttoppar i nätstationen från den årliga förbrukningen för uppkopplade kunder enligt den så kallade Velanders formel. För att utvärdera denna uppskattning av toppeffekten jämfördes nätstationens och underliggande kunders timförbrukning med de effekter som beräknats med denna formel. Resultatet av jämförelsen visade att formeln i vissa stationer överskattade eller underkastade storleken på den förväntade toppeffekten. Det förändrade energi-till-effektförhållandet på grund av laddning av en elbil gör att nya Velanderkonstanter behöver tas fram för hushåll med elbilsladdare. För att kunna göra dettaär det även viktigt att elnätsföretagen får information om montering av laddboxar och dess maximala laddeffekt. Historisk har elnätet ofta överdimensionerats, till stor del på grund av osäkerheten om förväntad förbrukningen och den ofta relativt låga kostnadsökningen medatt välja en grövre kabel i samband med utbyggnad av elnätet. Med elektrifieringen av fordonsflottan och produktionen av el med solceller hos konsumenter ökar belastningen på lågspänningsnäten och inmatning kan förekomma till nätstationer. Genom förbättrad mätning i nätstationer kan skillnaden mellan verkliga toppeffekten och dimensionerad maximal effekt minskas. Detta i sin tur kan minska behovet av nyinvestering i nätet för att klara energiomställningen. 

Ransomware has increased in recent years, which has caused many companies devastating consequences. Incidents with ransomware can seriously affect business processes and leave companies without the data needed to run and deliver mission-critical services.

This thesis is based on how to prioritize the threat of Ransomware in companies, authorities and municipalities. After years in the media about Ransomware attacks that have taken place against Swedish companies and authorities, this essay examines how well prepared and aware companies and authorities are about Ransomware attacks, everything from whether an attack has taken place, how they experience it and what solutions they have used to solve it.

Based on the literature study and investigation we have conducted about Ransomware attacks and in combination with the interview study, conclusions can be drawn that with various organizations in both the private and the public sector, there are different views and experiences about an increased threat. But both the public and private sectors have plans, routines and strategies against Ransomware-attacks.

The maritime transport sector makes a significant contribution to greenhouse gas (GHG) emissions, playing a consistent and increasing part in global CO2 emissions. Electrification of marine transportation is a key and necessary step for achieving the goals of the Paris Agreement and for avoiding the worst consequences of climate change. Sweden is among the first countries pleading for zero-emission transportation within 2045. However, one of the key challenges facing the widespread adoption of electric boats is the availability and efficiency of charging infrastructure. 

Wireless power transfer technology with more focus on inductive power transfer technology in the marine sector was investigated. The focus is wireless charging infrastructure for passenger ferries in Goteborg. Vesta was the ferry chosen for the case study and it operates on the Saltholmen to Vrångö route. The route, schedule, and ferry energy consumption were investigated to implement the wireless charging infrastructure. Swot analysis was performed to show the strengths, weaknesses, opportunities, and threats of the research. Based on this investigation, the power profile, energy storage, and adopted solution with its system were proposed.

In today’s society, high-temperature machines are prevalent across a range of applications that depend on the machines. They are used in power generation, industries, and the aerospace industry.

To enable these machines to perform their functions at these high temperatures, consideration needs to be given to materials, magnets, cooling systems, and insulation. At the same time, it is important to also consider machine safety, including the emergency of hazards and the environment impact of these hazards, and how to safely handle a machine.

This work aimed to gain a better understanding of today’s high-temperature machines and to observe how temperature is distributed across the motor’s stator and other components through simulations. The simulations resulted in a greater understanding of temperature distribution for both a passenger car, Nissan Leaf from 2012, and an aircraft motor.

The results showed different temperature distributions, with the Nissan Leaf representing what a standard motor typically exhibits today, while the aircraft motor displayed high temperatures, with the highest temperature occurring in the motor’s magnets.

A safe and reliable fault disconnection is an important function and preventive measure that needs to be ensured to avoid any damage that could damage equipment and injure person. Fault current value is a decisive factor that must be considered for safe fault disconnection. The report analyzes and presents proposals for a calculation method of dimensioning fault currents with respect to the tripping condition in a solidly earthed low-voltage network. The fault currents that the report deals with are single phase earth faults that are dimensioned when using fuses and two-phase short circuits that are dimensioned when using circuit breakers. By conducting a literature study and interviewing experienced engineers and project managers, various formulas and input data that are needed in the calculation have been taken out. Smart Power is an application that ABB uses to, among other things, perform various real-time calculations of short-circuit impedances, currents and voltage drops. The work's goal is to produce materials such as input data and formulas for Smart Power to be able to make calculations for single phase earth faults and two-phase short circuits in a directly earthed low-voltage network. A proposal for windows that can be implemented in Smart Power is presented in the report. How close the exact value is to the result is greatly affected by the accuracy of the input data to Smart Power.

The report shows how an approximate residual current value can be calculated with a limited need for input data so that it becomes manageable for a typical Swedish industry. A single-pole earth fault affects two phases in the feeding network, while a two-phase short circuit affects all phases in the overlying network.

En undersökning om hur Zero-Touch Provisioning (ZTP) kan effektivisera nätverksstu-denters laborationstillfällen, med speciellt fokus på Högskolan Västs studenter och lokaler. ZTP kan liknas vid plugin & play, det vill säga att ingen aktiv konfigurering från använda-ren krävs för att konfigureringen skall appliceras på nätverksenheterna. Konfigurering skickas i stället med hjälp av DHCPv4 och TFTP, vilka är installerade på en Ubuntu-server.Utförda tester visar en stark trend att ZTP tog kortare tid att applicera grundkonfiguration för att nå managementinterface via SSH. Även om ZTP är okänslig för tidslösande mänsk-liga felinmatningar av konfiguration, så visar tester att samma trend håller sig under både optimala och ”normala” förhållanden.

Rapporten utreder om distributionstransformatorer med märkeffekten 50 kVA i Vattenfall Eldistribution AB:s elnät kan avskaffas till förmån för märkeffekten 100 kVA. Transformatorer med märkeffekten 50 kVA förekommer vid nedtransformering av spänningen från 22 kV och 11 kV till hushållens huvudspänning 0,4 kV.

50 kVA-transformatorer skiljer inte särskilt mycket från transformatorer med den högre märkeffekten i fråga om storlek och pris, och de bedöms kunna bytas ut utan större praktiska svårigheter.

Fördelen med 100 kVA är att de elektriska belastningsförlusterna blir lägre i och med den högre märkeffekten. Dessutom innebär ett byte vissa elkvalitetsförbättringar.

Nackdelarna med 100 kVA är att de elektriska tomgångsförlusterna är högre och att inköpspriset är högre än för 50 kVA. I övrigt kan kostnaderna likställas för de två alternativen.

Endast kostnader för aktiva effektförluster berördes i rapporten då de ekonomiska kostnaderna för reaktiva effektförluster kunde försummas för de aktuella transformatorerna.

För att nå ett svar på frågan om det kan vara lönsamt att avskaffa 50 kVA-transformatorerna studerades fem verkliga fall i Vattenfalls svenska elnät. Dessutom studerades eventuella elkvalitetsvinster med ett byte.

Svaret blev att inte för något av de fem studerade fallen var det lönsamt med ett byte till 100 kVA-transformator. Rörande elkvalitetsaspekten blev svaret att ett byte visserligen innebär en skillnad men att andra faktorer oftast har större betydelse. Rapportens rekommendation blev att behålla 50 kVA-transformatorn i distributionsnätet. 

Elektrifieringen som råder inom olika branscher ställer idag höga krav på Sveriges elnät. Det väntas en stor effektökning som dagens elnät inte är rustat för och detta gör att elnätet på lokalnätsnivå behöver utvecklas och förstärkas. Syftet med arbetet är att undersöka huruvida det befintliga elnätet i området Överby iTrollhättan har kapacitet nog för det framtida effektbehovet som förväntas tillkomma i området och därmed säkra elleveransen till närliggande anläggningar och kunder. Arbetet innefattar nätanalys av utgående ledningar från två mottagningsstationer, M1 och M2, som är lokaliserade i närområdet kring Överby. Med hjälp av olika programvaror så som Mickel och MapGuide har detta arbete kunnat utföras enligt tidsplan. Effektberäkningar har gjorts utifrån data som insamlades via dessa programvaror och har använts för att analysera det befintliga elnätet. För att sedan kunna utföra en analys på hur framtiden kan komma att se ut har antaganden angående framtida effektökning gjorts. Effektökningen kommer till största del bero på tillbyggnad av bostäder och utökning av laddinfrastruktur för elfordon. På grund av att långsiktiga utvecklingsplaner för området saknas är framtida effektökning osäker. Två fall har därför tagits fram där olika effektökningar studerats.För det första fallet har en effektökning om 20 MW undersökts. Detta resulterade i att elnätet behöver utökas med nio nya kablar som beräknas vara belastade ca 50 %. När så pass mycket effekt skall tillkomma behöver ytterligare nätstationer placeras ut i området. Här motsvarar effektökningen 15 fullastade nätstationer med transformatorstorlek 1250 kVA. Kostnaderna för detta alternativ beräknas till ca 26 miljoner kronor. Det andra fallet innefattar en effektökning på 12 MW vilket resulterar i en förstärkning av elnätet med sex nya kablar från mottagningsstationerna. Här motsvarar effektökningen nio fullastade nätstationer med samma transformatorstorlek som tidigare nämnts. Kostnaderna för detta alternativ beräknas till ca 18 miljoner kronor.  

In Sweden, the number of rechargeable cars increases for every year. It is common to charge at home, for example because there is no need to wait for the vehicle to be fully charged.Charging at home takes place with low effects for longer time periods. The installation of micro production with photovoltaic systems is also increasing. Lidköping Elnät sees that the number of installations of chargers for electric vehicles and installation of micro production are increasing in the concession area and are expected to increase even more in the upcoming years. This study investigates the voltage variations that occur in an older and a newly constructed area with villas within the Lidköping urban area under normal load, as well as two future scenarios for micro production and chargers for electric vehicles. The work addresses which actions must be implemented in each area and what the actions cost.The voltage variations have been generated through calculations of the mentioned scenarios in the existing low voltage grid connected to the substation and the associated transformer in each area. Calculations on the low voltage grid at normal loads are based on consumption data take from Lidköping Elnäts’ system for debit measurement. In case of high production, a value is set for the photovoltaic systems that Lidköping Elnät considers as a normal size when a pre-registration of micro production is received. When charging electric vehicles, high consumption in the grid is assumed in the calculations. The voltage variations in the grid are added to the voltage variations occurring over the transformer to calculate the total voltage variations for the grid.Calculations of the total voltage variations in the grid for each scenario demonstrates that none of the points in the grid falls outside the limits allowed by the Swedish Energy Markets Inspectorate or European standard for voltage variations. At high production or high consumption the voltage increases or decreases for the weakest points fall outside the recommended limits for calculations. The high consumption scenario had the highest percentage differences form the reference voltage of 0,4 kV in both areas, which led to this scenario being used as the starting point for the development of actions.The actions developed reduce the voltage drops in both areas to be within the recommended limits of Swedenenergy, but also Lidköping Elnäts’ stricter limit for new connections. Lidköping Elnät is only obligated to implement an action if the voltage variations fall outside the limits set by the Swedish Energy Markets Inspectorate and the European standard or if complaints are received and poor power quality can be demonstrated.  

After the storms, Gudrun in 2005 and Per in 2007, the power grids in Sweden have replacedoverhead lines with underground cables. This is done to reduce disturbances for customers. However, with more undergrounding cables, there has been an increase in capacitive ground fault currents in the network. To counteract this, localized neutral point reactors, known as Petersén coils, have been placed in distribution transformers. Local Petersén coils are installed when the capacitive ground fault currents from the underground cables have reached a capacitive earth fault current between 5-10 A. The Petersén coil is then adjusted to match the same size of the capacitive contribution from the cable, but the coil's contribution is an inductive current, resulting in the currents canceling each other out. What is often not included in calculations is that the Petersén coil also contributes a small resistive component, which can lead to misleading calculation results. Additionally, the ground fault protections may not detect a ground fault if the resistive contribution becomes too large. This project has examined a network section at Lidköping Environment and Technology/Power grid, and the resistive contribution in the existing network section has been calculated. Based on the results comparisons have been made with the Swedish electrical standard that requires earth fault detection having a fault resistance of 3000 and 5000 ohm. But also find out if the set current and voltage values on the earth fault protection are able to detect an earth fault when the fault resistance is 3000 and 5000 ohms. With the help of a simplified calculation model that the project uses, it unfortunately turned out in the end, that this was not the case on all lines.

This thesis is about the preparatory design of the local network in a rural area on behalf of Vattenfall Distribution in Sweden. The project includes the replacement of 16 substations, 33 km of high voltage (10 kV) cables, 16 km of low voltage (0,4 kV) cables and the demolition of overhead lines for both low and high voltage.

The work involves two lines from a distribution station. One of the lines is new with an area of 240 mm2, it aims to take over the load in a newly built area with too high voltage drops that are currently fed from another distribution station. The newly built area has a voltage drop of 9% at present, with the new line the voltage drop will be 3.4%. The purpose of the second line with the area 150 mm2 is to replace the existing overhead line network with ground cables and connect network stations on the road. Because of difficult conditions the high voltage cables on part of the route are located in a lake. The network stations to which it is connected are updated because they are congested or do not have a divert option. 

The low voltages overhead lines that are connected to the affected substations are replaced with ground cables. The quality of the distributed electricity is analyzed at the connected low voltage customer by checking pre impedance, selectivity and voltage drops. 

Compensation of capacitive earth fault currents occurs on both cables, compensation is done with Petersén coils that are placed in substations.The cost calculation is based on a P1 level from EBR cost catalog and amounts to 36.8million SEK.

The cost was higher than expected due to several aggravating factor such as a higher number of substations and longer overhead lines than expected, and difficult ground conditions for the cables. 

As the medium voltage network cables in Sweden is buried down in the earth, the demand of fault localization expertise increases. To keep downtimes in the network short, the importance of effective fault localization is necessary. This work is aimed to map and visualize limiting factors within fault localization with focus on the TDR -

Time Domain Reflectometry. This work is a collaboration with Vattenfall Eldistribution AB.

Problems with fault localization on medium voltage cables with the TDR have been detected. A multiple factors are contributing to this problem. The results of this study show that the cable construction is a significant part in which extent the TDR can be used. The report are also accounting for basic information about construction and types.

The mapping also illustrates water treeing and how it affects cables in a negative way. Visualization of what causes water treeing and several actions such as triple extrusion, jacket testing and insulation testing is included in the essay. Further information about fault types, cable types, cable generations, instrument types and method types is given. All of them are affecting factors within the area of fault localization.

Documentation is highly important for a successful fault localization procedure, which is clarified in the report. Besides documentation the cable condition and the influence on it affecting the result of fault localization is stated.

A number of measuring methods and instruments are available to use when fault localization and testing are occurring. Every instrument has their own advantages and disadvantages. They also have their own respective area of usage. The basic principle of TDR is studied and explained accordingly. The other measuring methods, which are used in fault localization and testing, are shown more generally

eSite Power Systems AB recognizes the potential to improve their testing processes for system validation and verification. Presently, eSite utilizes lithium-ion battery packs for their testing, resulting in substantial energy wastage during charge and discharge cycles of the battery packs. To address this the company aims to shift to a real-time emulation method utilizing an accurate model of lithium-ion battery packs. This study presents the development of a real-time battery emulator designed to simulate the behavior of lithium-ion batteries based on the 3RC (Three Resistance-Capacitance) model. The emulator was developed to meet the requirements of eSite Power Systems, incorporating features such as real-time plotting and using the C++ programming language for compatibility with the eSite system. The battery model was validated using the emulator output during a pulse discharge test against synthetic pulse discharge test provided by MATLAB. The emulator's final parameters were validated through simulation and found to accurately represent battery dynamics. The successful implementation of an accurate battery model in a real-time simulation may reduce energy wastage but also advances the eSite Power System AB commitment to environmentally practices.

Borealis is a petrochemical company that produces base chemicals and plastics (polyethene and polypropylene). The production processes are very energy-intensive, and much electric energy is required. Borealis has several hundred distribution transformers worldwide to feed the necessary low-voltage switchgears. So far, no detailed recommendation has been made on how the distribution transformers should be protected, including how the earth should be connected. This means that every time a new distribution transformer is installed, the protection implemented depends on the engineering contractor and the Borealis responsible engineer.

This thesis evaluates the different protections required for distribution transformers in an industrial power grid.Focus has been on how the downstream protective earth (PE) and neutral (N) are connected, what type of earth fault and short circuit protections that are recommended, and what kind of overload protection is recommended (overload, thermal image, or temperature measurement). Also, the “normal” vendors' typical protection devices (Buchholz, overpressure, etc.) has been described.

A complete overview of the necessary protection has been achieved by describing the types of faults that can occur structurally and the protection required for each type. To decide what kind of earth fault protection that can be installed, the type of earthing system must be known. In the case of redundant feed switchgear, the type of circuit-breaker that is used for low voltage switchgear incomers and bus-tie (sectionizer) also need to be known, to identify where the earthing point can be made and what type of earth fault protection that can be installed. Another essential part of the distribution transformer protection is the selectivity scheme. Heavy process industries like Borealis have large direct online starting motors installed in their low-voltage switchgear and therefore a combined time-graded selectivity with inverse characteristics was deemed the most suitable.

This paper presents a power monitoring and control system for a medium voltage smart grid system. The smart grid interconnects the power sources between solar PV panel and 220V distribution network. This system consisting major components of inverters, measuring meters, solar charge controllers, relays, Arduino NANO and Raspberry Pi. The Current, power and energy readings are duly recorded. The Internet of Things (IoT) plays the vital role in the data communication between the sensors and electric power system. The voltage and current sensor data is used for the protection of power system network. In the traditional systems only the communication is uni-directional. The reliability of power supply is increased by used the bi directional network communication medium such as IoT. The tabulated results of voltage levels between 203.5V up to 212.8V shows the feasibility and effectiveness of proposed design. The proposed IoT model demonstrated the bidirectional communication from the sensors to the control unit and vice versa.

This paper presents a comparative analysis of electric machine designs for vehicle traction using traditional steel laminations versus soft magnetic composite (SMC) materials in four radial flux magnetic topologies: Rare-earth interior permanent magnet synchronous machine (IPM), wound field synchronous machine (WFSM), spoke-ferrite permanent magnet synchronous machine (SP-FER), and induction machine (IM). In total, 32 machine variants are evaluated considering different materials, and they are critically evaluated against a reference IPM traction machine with regards to performance, material cost and environmental impact. Results show that while the IPM design remains superior in performance for a fixed geometry, the WFSM and SP-FER offer significant environmental advantages. The WFSM emerges as the most eco-friendly option, while the SP-FER represents a balanced choice considering environmental impact, durability, production simplicity, and inverter complexity. This study highlights the potential of SMC materials compared to steel laminations in reducing costs (16 % to 29 %) and CO2-eq. emissions 21 % to 38 % in electric motor manufacturing without significantly compromising on performance, making it a viable alternative in automotive applications. 

This paper describes a method together with an implementation for automating the detection, identification and configuration of newly added resources and parts in a Plug and Produce system using OPC UA. In a Plug and Produce system, resources and parts are usually controlled by agents, forming a multi-agent system of collaborating resources. Hence, when a resource or part is connected to the system, a corresponding agent must be instantiated and associated with that specific device. In order to automate this, the system needs information about newly connected devices. This information could, for example, be positional data describing where the device is connected. Some devices like tools and parts to be processed have no own network connection, but still, they should get an agent with correct configuration instantiated. In this work, OPC UA is used for communication between devices and the corresponding agents. All agents and their communication are handled by an Agent Handling System, consisting of an OPC UA HUB together with functions for device detection and agent instantiation. The HUB is used for transferring data between devices and their agents in the network by OPC UA protocols. When a device is connected to the network, it is detected, and a connection is automatically created to the HUB that becomes configured for transmitting data between the device and its corresponding agent. © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

The climate goal can only be achieved by reducing carbon dioxide emissions. To do this, a transition from fossil-fueled vehicles to electrificiation of vehicles must take place. This has led to vehicles manufactures switching to producing more electric cars or plug-in hybrids, and production of electric cars has increased significantly during the year between 2015 and 2020. The report examines possibilities for installing charging stations in the car park at the residential property Skördetröskan 1, Trollhättan. The car park will have space for six cars to be charged with 3 charging boxes with double sockets of 22 kW. Type-2 connectors with semi-fast charging will be equipped. Load balancing must also be installed and will give a reduced total power of 40 kW instead of 66 kW if it were not included. But with the help of the dynamic load balancer, the entire system is protected from overload. In connection with the installation, a 0.6/1.0 kW low-voltage cable must be used by the NV1VV-R model. Which is fused with a 35 A fuse. 

An estimation of the cost of the project is described in the report with different price and alternatives at repayment period. One repayment period is 8,1 years and the other is 5,4 years. Why there will be different times is due to the fact that in a calculation, the investment support has been included. Which has led to a shorter repayment period. 15 000 SEK per charging box is the investment support from the Swedish government. A total of 45 000 SEK for this project. Revenues vary depending on how long and often the customer charges their electric car.

An estimated calculation has been performed on this calculation. The feasibility study is based on an estimated assumption and in the case of an efficient and profitable project, according to the author, a deeper insight and analysis as well as evaluation of suppliers is required. 

Traction batteries are used as an energy source in electrical vehicles and are composed of a various number of battery cells connected in series and parallel and packed in modules. SEM AB are developing electronic systems for controlling the voltage of a battery pack. The goal is to integrate the system for use in trucks. The system uses a microcontroller to control several transistors to connect and disconnect battery cells from the pack. If the system experiences a short circuit, internally or externally, high current can occur through the cells. A short circuit protection circuit is used to measure the current and disconnect the cells if the current is exceeding the maximum value allowed.

To ensure that the electronic short-circuit protection system complies with the requirements set by the client, the systems functionality must be verified by performing measurements at two different fault types: external and internal short-circuit. The fuse that is used as a secondary protection will also be tested to verify its function. The measurements are performed with a test setup which includes prototype circuit boards. The boards are modified to allow manual triggering of the transistors and to allow for measurements at selected points. A pulse generator is connected to one of the cards to control chosen transistors manually and thus simulate a short-circuit when the transistors are turned on. Selected properties are measured with oscilloscope, multimeter and Rogowski coils. The data from the measurements are then processed in Matlab.

The results from the measurements show that the short-circuit protection system opens the circuit within 1 μs after the current measurement circuit detects a current which exceeds the threshold value of 62,5 A. Due to the design of the circuit board, the current measurement circuit does not measure all the current. This can lead to higher short circuit current than the current measured by the sensor. Also, the current through an individual current sensor cannot be measured with the available equipment. When tested, it takes 750 μs for the fuse to blow at 25 V and the current achieves a maximum value of approximately 2000 A. The high current can cause damage to sensitive components and battery cells due to excessive power dissipation. The digital signals that turn off the transistors during a short circuit are affected by some interference. This can cause misread signals and can reconnect the battery during a short circuit. The distortions can be caused by the design of the circuit board. For example, if high current carrying paths is placed close to the path of the signal the distortions may be caused by electromagnetic interference.

Electricity production in the Swedish power grid system has during recent years experienced a major change where there has been a large-scale expansion in renewable electricity production. This have brought significant challenges to the Swedish power system, to be able to maintain a stable power system, a great need for frequency regulation is required. The thesis is carried out in collaboration with Rabbalshede Kraft and will investigate the profitability of three cases of frequency regulation, using differing power sources, from an existing wind farm that supplies the frequency maintaining reserve FCR. The report’s focus is examining the financial profit for the various cases based on historical data from the years 2021 and 2022. The three cases investigated in this thesis is frequency regulation with only the wind farm, frequency regulation with a battery plant that has the same connection point as the wind farm, and a combination of these, where the wind farm supplies FCR-D Down and the battery plant FCR-D Up. To determine the profitability, a calculation model was developed as well as a bid strategy and frequency data processing program. The model is based on historical data from market prices, frequency data and production data from the wind farm. The bidding strategy for FCR-D with the battery facility is conservative as recovery of the battery takes place every two hours instead of delivering the service every hour without recovery, which is likely possible. However, this possibility is not investigated in this report and therefore, a conservative strategi is used to ensure the fulfilment of the conditions of delivering the service. This strategy leads to a halved approximated profit. The bid size for the wind farm is set to 5% of the instantaneous output for the hour of operation. For the cases investigated, the profitability varies depending on the support service delivered and the payback period for the battery plant. The best results for the different cases are as follows for 2022:

• Case 1-Frequency regulation with only the wind farm: FCR-Down 1.52 MSEK

• Case 2-Frequency regulation with only battery system: FCR-D Up 2.92 MSEK, 2-year payback period.

• Case 3-Frequency regulation combination: FCR-D Down and FCR-D Up 4.44 MSEK.

This study’s most profitable result is obtained with Case 3 where a combination of the wind farm and the battery plant is used. To start delivery of support services, it is required that the wind farm and battery facility go through a pre-qualification test.

The automotive industry is heading for an electrified future and that brings new challenges for the validation processes. This thesis project was carried out at Volvo Cars in Gothenburgat their validation department for electrical propulsion. The goal of this thesis is to propose a test method for measuring bearing currents in a permanent magnet synchronous machine. Bearing currents are electrical discharges between the rotor shaft and stator frame going through the bearings. These discharges can damage the bearings and thus is a large contributor for premature failure in electrical motors. By reviewing and evaluating several methods,two final methods were chosen for future testing. The two chosen methods were insulated bearing current- and shaft voltage measurement. A physical validation of bearing insulation was attempted without success, even thou these methods are still recommended for future work.

A computational hybrid energy storage system (HESS) model was developed in Python, comprised of a vanadium redox flow battery (VRFB) and a super capacitor (SC). Different sized HESS were applied to the use-case of a 50-vehicle public EV charging depot, to take advantage of dynamic electricity prices during the day and to reduce the cost of electricity incurred by the EV charging service provider (EVCSP). Fifteen sizes of HESS were evaluated for this application, comprised of 10 – 50 kWh VRFBs and 5-15 kW SCs.

First, the VRFB was assessed using a multi-period optimization genetic algorithm (GA) to find an optimum charge and discharge schedule over a given monthly EV charging load profile. The simulations showed that incorporating a VRFB to an EV charging depot resulted in cost savings when compared to a depot with no storage. The cost savings amounted to $1.13 to $6.19 per day, corresponding to $380.72 to $2,068.04 of costs saved annually. A greater cost reduction was observed for a greater VRFB size.

The results of the GA showed signs of optimization, where the residual load was greater compared to the EV charging demand during times of low-cost grid electricity, due to the VRFB charging to take advantage of the lower energy costs. During times of high-cost electricity, the residual load was lower compared to the EV charging demand as the VRFB would discharge to supplement the EV charging demand.

A net present value (NPV) calculation was performed to consider the discounted cashflows and VRFB capital cost over a 20-year period for each VRFB size. This yielded strong positive values ranging between $436,600 - $448,485, and the NPV decreased for increasing VRFB sizes due to their high capital costs. The best NPV was $451,800 for a charging depot with no storage. The high capital costs for the VRFB outweighed financial benefits from energy cost savings, and to obtain a NPV equivalent to the ‘no storage’ option, the VRFB capital cost would have to decrease from $650 /kWh to $360 /kWh.Following the VRFB study, SCs of varying sizes were implemented to understand whether further energy cost savings could be achieved.

The SCs were implemented using a rule-based strategy, where they would charge/discharge depending on the charging schedule of the VRFB, to provide additional arbitrage and to reduce the remaining EV charging load that was not covered by the VRFB. The SCs carried out 2-3 discharge cycles per day, and due to their low energy density, they could not carry out sufficient energy arbitrage to make any meaningful cost reduction. A final NPV calculation was carried out for each VRFB+SC combination, which resulted in lower NPV values than those determined for the VRFB only. This was expected due to the SC’s high capital costs and minimal energy cost reduction.

This paper presents a techno-economic analysis for the optimal sizing of a Hybrid Energy Storage System (HESS) integrating a Redox Flow Battery (RFB) and a Supercapacitor (SC) for an Electric Vehicle (EV) charging station. The SC is used for shaving noisy peak loads and ensuring grid stability, while the use of RFB is optimized through genetic algorithm-based multi-period optimization considering time-of-use (ToU) pricing and energy arbitrage. The profitability of HESS is analyzed and evaluated, and the results indicate that, with the current capital costs, utilizing HESS for this specific use case may not always be directly profitable. However, if installation costs were to decrease, employing HESS can become economically advantageous. Additionally, the management tool and optimization algorithms developed for HESS can be highly beneficial in a wide range of other scenarios.  

Då entreprenörer utför felavhjälpningar och schemalagda underhåll i Vattenfall Eldistribution AB nät upptäcks regelbundet fel och brister. Dessa brister ska de enligt serviceavtal rapportera in och göra en beställning på arbete, ett åtgärdsförslag med hjälp aven applikation. Det sker regelbundet att dessa brister inte blir inrapporterade korrekt vilket leder till felaktigheter i budget, kvarvarande noteringar i SCADA-systemet som inte avslutas och att underhåll inte utförs. Detta är ett problem som har pågått under många år och som är svårt att få ordning på.

Detta examensarbete är ett uppdrag från Vattenfall Eldistribution AB och behandlar processer för drift och underhållsåtgärder och har till syfte att analysera brister i de befintliga processerna och ger förslag på åtgärder. Analysen baseras på intervjuer med drift- och underhållspersonal.Det resultat som framkommit av utredningen, visar att det krävs både tid och budgetvanaför att skapa dessa beställningar genom applikationen, vilket gör inrapporteringen omständlig för många tekniker. Det blir informationsöverlämningar vilket är ineffektivt då beställningen inte utförs direkt och det kan leda till att viss information försvinner eller glöms av. Flera alternativ som dellösningar har tagits fram och kan kombineras och användas beroende på vilken inriktning Vattenfall Eldistribution AB vill ta. Alla alternativ som tagits fram kräver någon form av större systemförändring

In this study are rebuilding methods to improve existing low voltage networks (0,4 kV) investigated. The background, causing the need of improvement, is the existence of lines where the trigger condition is not satisfied. Due to the length of the line and its area a problem with power quality is also often present in these lines. The meaning in this context of not satisfying the trigger condition is that intended fuse will not disconnect in prescribed time of 5 seconds when a single phase fault to ground occurs at the line. Why this problem is emerged can depend of load increases by time, thus the fuse size has been increased which causes the demand of a higher fault current to disconnect. In this study a large part of the focus is placed in satisfying the trigger condition and a small part of the focus is placed in improving the power quality.

The traditional solution to solve above problem is to expand the medium voltage network, closer to the customer, or reinforce the low voltage network, two comparative expensive solutions.

The studied methods are named alternative as either the methods are less known or entire new which are not fully developed so far. Respective method consists of a device that by design, and chosen point of connection at the line, is considered to afford a gained single phase fault to ground current. Four devices are studied and named

Isolertransformator (eng. Isolating transformer), Sparkopplad transformator (eng. Auto transformer), Magtech Voltage Booster and Black box. The devices are studied in computer aided simulations with the program PSCAD/EMTDC and the result shows that all devices increase the fault current. The device Isolertransformator affords the highest gain. Further an economic comparison is performed regarding purchase cost and no-load losses, the result is that the devices Sparkopplad transformator and Black box has the lowest costs and losses

The substation called Magnetgärdet is located in Ludvika, Sweden and it is owned by Västerbergslagens Energi AB. The substation has recently been renovated and is now placed indoors, which reduces the influence of weather on the station. To decrease the need for personal supervision and increase the availability of the station a monitoring solution is needed.

The purpose of this degree thesis is to examine if it is possible to monitor the condition of critical items in the station with infrared cameras. To determine this, theory on condition monitoring, thermography and thermal imaging cameras has been compiled together with relevant measurements and tests. The results are then discussed to see if a possible solution can be presented. Important criteria for making condition monitoring with infrared cameras possible have also been formulated in this degree thesis.

The conclusion is that it is possible, but a complicated system is required. The solution we have given is based on different parts interplaying with each other and it should become a powerful monitoring system. It is however uncertain whether infrared cameras are the only and best tools, therefore other tools should be considered. It might be possible to use thermistors with, or instead of infrared cameras.

Zambia Electrical Supply Company (ZESCO) Limited has partly replaced electrical components from analogue to digital in the auxiliary system at Kafue Gorge Power Station. Later, it was discovered that there was an increase in component breakdowns in the parts of the monitoring system connected to the auxiliary system. The company seeks baseline data for Power Quality to help determine the cause of these frequent breakdowns.

Unilyser 902 and PQ Secure were used to monitor and analyse the power quality outlook in both the auxiliary and distribution systems. Data was collected on 3 deferent points of the systems. These points were different both in space and electrically and were connected to loads with different electricalcharacteristics. There were inconsistences in the data collection procession such as deferent lengths in times of motoring per point and difficulties in reaching one of the pre-selected points. Furthermore, the monitoring instrument could not be correctly configured because a correct IP address could not be obtained. This led to inconsistencies in data collection such as failure to obtain certain power quality parameter readings. No particular power quality issues could be pin pointed in the system that could be linked to the problem at the station. However, due to the above mentioned challenges in the data collection process, these results were inconclusive for the purpose of the study. The results arrived at cannot serve as baseline data for trouble shooting the system. More concrete and updated monitoring of power quality is needed to draw conclusion about the wellbeing of the system from the power quality point of view.

In view of the above, it was recommended that permanent power quality monitors are more suitable tools for the purpose as they give more updated data. The updated data can be relied upon and compared with other points monitored at the same time and this gives a more fair understanding of instantaneous and non-repetitive events in the power system

This thesis explores the effectiveness of grounding devices and explores causes and mitigating of electrical discharge machining (EDM) in bearings used within oil-cooled electric motors powered by pulse-width modulation (PWM) inverters. While grounding rings are a common strategy to divert Common mode, capacitive, and high-frequency currents away from bearings, their effectiveness can be reduced in oil environments as different EDU cooling and lubrication systems have different impacts on grounding devices.

This research proposes a combined approach utilizing microfiber grounding rings and ceramic insulated bearings and use of conductive bearings. In this literature explanations of different bearing currents and bearing failure modes are discussed and also the test setup and installation of EDU are explained to measure the bearing currents and voltage. Different viable solutions are also proposed to mitigate the bearing failures. The high conductivity of the fibers in the grounding ring should effectively channel unwanted currents, while the inherent electrical resistance of ceramic bearings minimizes current flow within the bearing itself, offering a more robust defense against EDM in oil-cooled electric motors.

In this report, we present a photogrammetric system that can be used during welding operation with a robot. It should be able to give the position and the orientation of the Tool Center Point with a high accuracy (less than 0.5 mm). After a view on the historic of PosEye®, we describe its two different ways of working: using active or passive markers. We then explain one way to improve the accuracy of the sensor by taking in account the distortion of the image due to the projection. This part is followed by investigations on a so-called “flash collar” which permits to fix diodes when we use passive markers. We finish by some tests to have a better idea of the accuracy of the sensor. This accuracy is only available for the position, as it has been realized on a Coordinate Measuring Machine which is only able to give information on its position.

When a lot of new construction occurs in an area, the power grid structure must be analyzed to ensure that the existing network can handle the new power demand. In Forshälla, summer cottages have been converted into permanent residences, new residential areas have been built along the coast, and households are installing solar panels and electric vehicle chargers in their homes. In this thesis, the 10 kV power grid for the Forshälla area will be analyzed, and a proposal will be developed for improvements to the power grid structure. The Forshälla distribution station will receives six new switching compartments, which will lead to more switching options in the area. Cable with an area of 50/95 mm2 is replaced with 150 mm2 cable to ensure a stable and reliable power supply for customers. Currently, the Forshälla area has 2447 customers distributed over 1889 connection points, with 843 of the customers residing in urban areas and 1604 people in rural areas. There are a total of 128 substations, 116,5 km of 10 kV medium voltage cable, and 265,8 km of 0,4 kV power cable within the area. In the development of results and methodology, the energy companies planning, and preparation handbook has been used to plan and structure the work as efficiently as possible. The authors proposal for the new power grid structure includes laying 19,36 km of new medium voltage cable, of which 3,5 km is replaced power lines and the remaining is replaced underground cable. Two of the six new switching compartments in the distribution station are used to balance load currents and create more switching options in the network. Five junction boxes have been demolished, five network and two series satellite stations will be built. The maximum voltage drop decreases from 5,50 % to 3,30 % during normal operation. The total cost for the proposed new power grid structure is approximately 7,7 Mkr. Calculations regarding slow voltage changes that occur when connecting solar cells meet the requirements of ±10 % imposed by EIFS 2013:1. Conductor impedances for the solar power systems were neglected in the calculations, which may cause the actual value to deviate slightly from the results presented in the report.  

Today more and more overhead lines are replaced by underground cables as a result of storms which have caused major interruptions in the power grid. Because of the cabling, the characteristics of the power grid change and the calculations for the relay protection settings that are made today need to be reviewed if they still can be performed in the same way as before. This to ensure correct and selective fault disconnection. This report, in a simplified way, explains how resistive zero-sequence currents flow in the grid and how they are measured by earth fault protection.

A fictitious 22 kV grid has been studied and earth faults on two different cables in the grid are analyzed and discussed. Calculations are made with different sizes of the zero-point resistance resulting in different resistive zero-sequence currents in the grid. This is done both in normal operation and reserve power operation to be able to study differences that can occur. Discussions are made regarding misalignment, imbalance, angle error and measurement error, which have not been included in this work. The conclusion from the study performed is that it is difficult to parameterize a directional earth fault protection and a zero-point voltage protection correctly to be able to secure a correct disconnection in both normal and backup operation. This is because of the various resistive zero-sequence currents that arise in the grid. 

Unipower AB had a big project in the Sultanate of Oman installing 200 power quality measuring devices in 50 substations in the outskirts of the city Sohar, and also smaller projects in the city Muscat. Finishing the project and summing up the lessons learned will be the main goal of this project.

Connection Problems were encountered with the measurement equipment in the Sohar region, about 20% had connection, the rest had no connection at all. The goal was to find a solution to the connection problem. At the end the solution was to establish the sim cardsof the routers in every station, even the stations that work. That required a presence in Oman and to access to the stations.

Other goals were to have meetings and discussions about different solutions, ideas or upgrades for the other customers for Unipower in Oman.

The work include an analysis of the procedure of the installation work in Sohar as well in Muscat and also a white paper on the experiences gathered. A project list was created based on these experiences.

The conclusion is that about 85% of the stations in Sohar now works, the other 15% does not work due to no reception inside the stations. Tests were made Showing the signals available hence the solution is to use an antenna outside each station to get a signal for the router.

Electricity consumption in Sweden is increasing and more local grids need to be expanded or re-dimensioned at the same time as we are facing a massive energy transition with the installation of renewable energy sources. Solar panel installations and charging stations for electric cars are becoming more common among private households, contributing to voltage variations in the local grid that affects power quality. Vinnergi AB in Trollhättan, which prepares local grids, wants to analyze how this might affect future projects regarding voltage variations, including voltage drops and voltage rises.

There are several methods for calculating voltage drops. Including the extreme case of 'minimal production and maximum consumption' and calculation using aggregation with aggregation factors and Velander’s method. Velander’s method is most suitable for calculating voltage drops in existing grids but requires information on annual energy consumption, which makes it unsuitable for new installations of charging stations. Aggregation factors may be more suitable in this case. When calculating voltage rise during the installation of solar panels for private use, it is evident that the position of the sun relative to the solar panel has a significant impact on production levels.

Therefore, some form of aggregation method regarding power flow in this type of production will be necessary for these calculations. Further research regarding an aggregation method for these types of approximations is necessary. In these scenarios, the total length of cable from the feeding network station to the customer has some impact on voltage variation.

Furthermore, the impact on the local grid from large solar panel installations on the high-voltage side of a grid station is investigated. It turns out that the voltage rise from this affects all customers in the underlying network roughly equally, regardless of their location in the grid. For a planner, this may be an aspect to consider as all types of power production are increasing.

In the future, a planner may need to consider several factors regarding voltage variations in local grids to avoid further interventions in the foreseeable future, which could potentially incur additional expenses for the power grid companies.

The aim of this paper is to present the eddy current losses in solid pole shoes in a permanent magnet two-pole electric motor. In the presented paper, the authors have chosen to work with three different analytical models, Carter’s theory, Gibb’s theory and Lawrenson’s theory, each with different degree of accuracy and simplifications. The results from the analytical models all present relatively low eddy current losses, giving the designer valuable arguments to utilize solid pole shoes, as a rotor with solid poles is from a construction point of view a more suitable choice, increasing the mechanical stability and reducing the production cost, compared to the laminated design.

Even though the magnetic circuit of a linear electric machine is very similar to a rotating electric machine, they diverge in one fundamental property. The linear generator is open in both ends, i.e., the magnetic circuit is non-symmetric. This paper investigates and discusses the drawbacks of this non-symmetric design in a linear permanent magnet generator, installed in a wave energy conversion system. A two-dimensional geometry has been utilized for the numerical calculations in a finite element method simulation tool. The results present an increased cogging force and significant core losses in the translator as consequences of the longitudinal ends in the machine. © 2020 by the authors.

The hurricane Gudrun in 2005 left major damages on the Swedish grid. Therefore new grid regulations concerning downtime were implemented in Sweden. Resulting overhead lines were replaced with underground cables. The first well known effect of underground cables during a fault is the generation of capacitive earth fault current in the grid. The second well known effects are intermittent and transient earth faults in the underground cables. These faults usually occur in cable joints or other insulation defects in cables. It has been found that the recent earth fault protections have problems with detecting intermittent and transient earth fault, this in turn causes disconnection of the power transformer which yields a non-selective disconnection at the distribution system. This work has been carried out at Göteborg Energi Nät AB. The purpose of this work is to study and examine how some of the most common earth fault relays on market detects and manages intermittent and transient earth faults. The study shows that the fault detection became more complex by increased generation of capacitive earth fault currents. The main reason is that the resistive part of the fault current is too small in comparison to the capacitive part. Therefore the Petersen coil compensation calibration is vital in order to minimize the generation of capacitive earth fault currents. The study finds only minor theoretical differences between the intermittent and transient fault detection. One deviation found was in the protection MiCOM P132 which is designed and constructed with an analogue detection circuit in order to enhance the protection functionality. The remaining earth fault relays are designed and constructed with digital technology. The major difference between the digital technique relays is that the sampling rate is different in different models. A well calibrated compensation simplifies fault detection which results in simpler earth fault protection relays meet the detection requirements of the represented company. To achieve accurate results, live tests are highly recommended

In connection with Västra Götaland setting a regional climate goal to be fossil-free by the year 2030, the city of Trollhättan adopted the same goal. Part of the transition to becomefossil-free is to increase the proportion of electric vehicles. This means that an expanded charging infrastructure is needed, and above all an expansion of the public charging infrastructure. For those who live in the central district of Trollhättan without their own or rented parking space with charging options, this can be considered as an obstacle to switching to an electric vehicle. 

When planning the new charging stations, not only does the municipality requirements for the city plan have to be met, the existing electricity network in the area must also have sufficient electrical capacity. This means that the electricity grid must be able to handle the increased power consumption. Charging several electric cars with high power consumption at the same time results in a peak in power consumption in the grid. To prevent this, load balancing and so-called “smart charging” can be used. For the grid company, this means that the electricity network does not risk being overloaded and that the existing network station transformer does not need to be replaced. For the electric car owner this can mean a decrease in charging costs as the charging is done when the electricity price is lower.

The authors of this report have chosen a selection of streets in central Trollhättan as proposed locations for the charging stations. These streets were chosen by taken both the surrounding environment and the regulations is the city plan into account. In the southern part of the city center, the charging stations can be used mostly by residents in the area. In the northern part of the city center, the charging stations can be used by residents as well as visitors to the city center. This benefits the business community as long-distance guests can use the charging stations. By limiting the power output at the charging points the risk of overloading the existing electricity network can be avoided. This means that a lower main fuse can be selected, which results in lower costs. Of the 7 proposed streets, only one of the streets, Charging station 7, will have a limited capacity. If the capacity of Charging station 7 shall increase it will require a replacement of the local substation’s transformer.

The conclusion of the report is that there is a need to review the charging infrastructure in central Trollhättan. Demand for charging stations will increase as the sales of electric cars continue to reach new heights in the future. 

In today's network, automation tools are becoming more and more important. This thesis report is about a comparison of two automation tools Ansible and Puppet bolt. Among other things, it has determined which tool is best for the people who use them and which tool has the best performance.

Ansible is an agentless tool that uses YAML for it’s scripts. The scripts are called playbooks and these have plays inside them. Inside the different play, there are tasks that perform certain tasks. Puppet bolt script is called manifests, there are also tasks that can use most languages. Puppet bolt is also agentless that can be used for the same areas as ansible.

Which tool is the most complicated? Which tool has the best performance? Are two questions that can determine which tool is best. To answer them, tests have been performed. We can see which tool is the most difficult to use and install. Which is the fastest and most efficient for the computer on which the tool is installed. The language that is the most complicated is also displayed.

After these tests are completed, the results show that ansible is the most effective. Ansible is the fastest to complete the configuration. Ansible also has a less complicated installation. There are certain factors where the Puppet bolt is better. But the tests that Ansible was better at was the biggest factors. 

This report deals with electromagnetic compatibility (EMC) regarding ignition systems developed by Svenska Elektromagneter AB (SEM). In today's automotive industry, EMC is an area that is becoming more and more relevant to work within. Ignition systems are regarded as the one of the biggest EMC problems because it radiates much energy over a wide frequency band [1]. EMC problems that are discovered early in the development process are cheaper to correct than if they were discovered later.

EMC problems that are not identified/addressed in time can lead to serious consequences for the consumer. An example of this is Toyota in 2009 where EMC problems with their throttle control unit caused deaths and large financial losses for Toyota [2].

The report shows that measurements on the electromagnetic fields (E-fields and H-fields) can identify where in the ignition system the electromagnetic disturbances propagate from. Relative measurements have been made on different combinations of interference-dampening solutions. The interference-dampening solutions consist of various cabling, high-voltage resistors, and filters.

This report focuses on identifying and mitigating the electromagnetic disturbances but does not consider other aspects such as spark quality or timing. Measurements and tests have been carried out on a simple test arrangement using just one ignition coil. Problems that may arise with more complex systems are not covered by this report.

The results show that the disturbances are emitted from the low-voltage cable and are caused by self-resonances in the ignition coil and by the spark. The results show that high-voltage resistors, cabling, and filters have a dampening effect on the disturbances. Using a shielded or braided cabling is an easily accessible option to get a dampening of the interference. The use of filters attenuates the disturbances but needs to be investigated further to see if it is applicable to the product.

Vindkraftverk ansluts idag i snabb takt till elnät runt om i världen. Elnäten är ofta inte tillräckligt dimensionerade på platser där vindkraftutbyggnad är lämplig vilket leder till ett behov av nätförstärkning. Förstärkning sker konventionellt genom att övergå till en högre spänning, något som kan vara förenat med stora kostnader och ledtider. Bland annat därför har en filosofi med beteckningen smarta elnät uppstått, som handlar om hur elnätsystemet ska se ut när det är mer anpassat till de nya energikällornas karaktär och samtidigt medför ett mer effektivt totalutnyttjande. För vindkraftverk kan det då handla om att i högre grad än idag reglera produktionen och understödja nätet, t.ex. via intelligenta kontrollsystem, kraftelektronik och energilager. I den här rapporten undersöks hur mycket vindkraft som kan anslutas till ett svagt elnät då principer för smarta elnät tillämpas och för att se om kostnaden blir lägre än anslutning via konventionella nätförstärkningsmetoder.

Det svaga elnätet som studien bygger på ligger i Tidaholm. Vindkraftseffekten som ska anslutas är på 62 MW. Begränsningar i befintliga regionnätets ledningar gör att 60,3 MW kan anslutas med principer för smarta elnät, fast det finns flera skäl till att anta att den fulla mängden vindkraft går att ansluta. Detta till en kostnad som väsentligt understiger kostnaden att förstärka nätet på konventionellt sätt, kostnadsbesparingen uppgår till ca 58 % eller ca 95 Mkr.

On behalf of Vinnergi the students have carried out the degree project, where the purpose of the project was to find new smart opportunities to simplify the working methods in a preparation of electricity grid. The process today is outdated because the planner works with printed papers and documents and not in digitized programs.

To find more knowledge about the planner’s working methods EBR’s planner’s manual has been studied. The project deals with a summary of the planner’s working methods, agreements, permits, commonly used tools and software. Semi-structured interviews were made with experienced planners as a base for identifying which development areas the students would focus their efforts on. After the interviews it could be stated that the mapdata that the planner uses in his work is in need of development.

Several checks of how various programs that handle digital maps and geographical information such as GPS, Qfield, QGIS and Input have been investigated and problematized based on the mission’s goals and purpose. The tools that lived up to the expectations of being synchronized with each other were QGIS and Input. QGIS is used on computers where the base map is drawn in different layers such as excavation lanes, power stations and cable distribution cabinets. The software makes it possible to manage and change the different layers during the project, it becomes a living file. Input is a free application that is based on QGIS which can synchronize the projects. This allows the planner to make changes out in the field, as the objects that are added or deleted in either QGIS or Input changes in both programs.

To digitize and visualize any changes, an investigation was made to find whether Augmented Reality (AR) and 3D-models could be implemented and used in field visits together with the landowner. AR is a way to amplify reality and make it possible to add virtual objects in real time, some examples are PokemonGo or various Snapchat filters. In a program called SketchUp 3D-models are created and with help of AR the models can be applied in the environment where the user is located. The user can place the object and change its size.

After completed work it could be concluded that the planner’s work with the map data can be digitized and simplified with the programs QGIS and Input. The use of AR and 3D-models can be helpful when contacting landowners.

Analog circuits are often specified using non-linear equations, which are difficult to analyze. Therefore, test generation and diagnosis are problematic issues in practice. In this paper we propose a new method for diagnosis of analog circuits that uses combined information from tests at different frequencies. By solving simultaneously the resulting equations (one for each test frequency), we get a reliable method that decreases the number of possible answers to the diagnosis problem. The min-max optimization algorithm that we implemented for non-linear transfer functions gives good average runtime for diagnosis parametric faults.

In recent years, electric vehicles and micro-production from solar panels have become very relevant topics. Customers have started installing electric vehicle chargers and solar panel systems which can impact the grid capacity. Due to the expected increase in solar panels and rechargeable vehicles, Vattenfall Eldistribution AB wants to investigate how micro-production and electric vehicle charging will impact the low voltage network at a substation.

In this thesis, calculations have been performed in NetBas for various scenarios depending on whether the customer facilities are considered as a production source or a consumption building. Different scenarios have been assumed to observe how a 500 kVA transformer and cables are loaded or unloaded in the various scenarios. Two out of the four scenarios performed are dimensioning cases, meaning scenarios with full production and no consumption, and vice versa. The remaining two scenarios are in normal mode and in micro-production depending on the main fuse size so that the total power production from all micro-producers under the low-voltage network does not exceed the limit of 150 kW set by Vattenfall Eldistribution.

The stationary voltage variations during the connection and disconnection of micro production units are at 0.92% of the nominal voltage, which is an acceptable value. Voltage changes calculated using NetBas comply with the requirements according to the regulation EIFS 2013:1, the standard SS-EN 50160, and Vattenfall's planning handbook. However, voltage variations in scenarios where 50%, 70%, and 100% of customers have micro production have exceeded the allowed limits. Sometimes, the problem can be solved by manually adjusting the transformer's turns ratio using a tap changer to ±5%. But a winding tap changer is a more suitable solution where all voltage changes that occur on the grid can be corrected during operation and automatically.

It has been established that the cables are appropriately sized for all load scenarios, except for one cable which was found to be overloaded in the 100% scenario when all 58 customers are micro-producers. To address this issue, the cables should be paralleled to avoid overloading. In this thesis, manual calculations have been carried out to compare with the NetBas calculations, and the results were found to be almost identical. The calculation results fall within the limits set by the Swedish Energy Markets Inspection Authority, the Swedish Electric Standard, and the ALP report.

This thesis follows the design of a customized battery pack solution for EV conversion. The design focuses on the Toyota Land Cruiser 70 Extended model, a modified 7-seater for use in safaris and tours.

The aim of this research is to analyze, review, and to design a customized battery solution for the EV conversion of the Land Cruiser EV conversions that are currently being built.

he methodology for this research follows the analysis of the current EV conversion systems, their power and range requirements, as well as analysis of the battery configurations currently in use by the same systems. Additionally, the physical available space for the batteries, including their location and the weight of the battery packs is also considered.

These data are then implemented in the design of a novel battery pack system with various capacities and configurations, depending on the power demand and range requirements of the EV conversions being done.

The results of this research show that an improvement in overall battery capacity, which translates to higher range, is possible, as well as providing flexible configurations of various different capacities based on the cost constraints and performance requirements of the overall system. Additionally, a 12v Auxiliary battery pack design is also presented, which replaces the 12v Lead-acid battery being used currently, for a higher capacity and longer life for the same.

Public transport has long been characterized by vehicles plying the roads in cities. In connection with electrification, new opportunities have been created to explore a more environmentally friendly approach for people to move. By creating the conditions to get around via waterways, these resources can become part of public transport.

The purpose of this degree project is to design a model of an electrical system consisting of two electric drive lines, an auxiliary system and an emergency system for an electric passenger boat. Which error outcomes may occur are also investigated. System design has been used to develop the model.

The result contains several drafts to build a basis for improvements. The first draft is based on requirements that existed from the company and consisted of a simple model with three systems which, according to the requirement, are independent of each other as much as possible. This meant that each new draft received a simpler model, as the redundancy is most easily achieved through parallel connection. As soon as components are put in series, a dependency between components is introduced which this work wanted to counteract.

The conclusion is that by building a simple model where the components are laid in parallel with switches, redundancy is achieved while only the components that are relevant at the specific time are used. For example, this means that the entire system for mooring can be switched off with a switch when the boat is out in traffic and thus not disturb the remaining consumption. As this boat is intended to take passengers, it is important to achieve the highest possible safety.

In addition to the redundancy, an analysis was also made of various error outcomes that could be counteracted. The energy supply to the boat is important and hence the choice was made to use batteries with contactors to enable the use of one battery at a time or both at the same time to ensure that the boat has good options in the event of a failure from the energy supply.

Detta examensarbete är en beredning för Fortum Distribution AB. Avsikten är att ansluta två stycken nybyggda vindkraftverk till det befintliga elnätet. Samtidigt genomförs en förstärkning av distributionsnätet genom kablifiering (kabelförläggning i mark) samt rasering av det befintliga luftnätet. Platsen för projektet är belägen strax norr om Mariestad.

Projektet är uppdelat i tre deletapper. Deletapp ett (huvudprojektet) heter Vindkraft Lyrestad – Värlsen. De nybyggda vindkraftverken i huvudprojektet kommer att anslutas till ställverket i Lyrestad.

Gällande deletapp 2/3, högspänningen 10 kV, kommer matningen till distributionsnätet från en befintlig stolpstation L9083-40054 som står i Ödegården. Stolpstationen som står i Ödegården kommer även att mata fem nya markstationer längs sträckningen. Lågspänningen 0,4 kV kommer idag från stolpstationer som kommer att raseras och ersättas med markstationer.

Beredning är utförd av Jonas Gustafsson på konsult företaget PSN Kraftkonsult i Vedum.

Hela projektet omfattar ett 15-tal berörda lågspänningskunder som kommer få sin servis nedgrävd samt en schaktsträcka för högspänningskabel på ca 8 km. Detta är fördelat på sträckningen mellan Lyrestad – Värslen via fem stycken nya markstationer. 

This report contains a study of power flows in Uddevalla Energi AB receiving stations and optimization of the operation control of its power capacitor batteries and transformers.

For the past thirty years, Uddevalla Energi AB has employed power capacitor batteries almost all year around and these need soon to be replaced due to ageing. Uddevalla Energi Elnät AB has a need for new procedures for the operation control of the power capacitor batteries following new regulations introduced by Svenska Kraftnät and Vattenfall AB for reactive power flows on the grid.

In the study of power capacitor batteries, there has been an investment calculation with three alternative purchase options. Option one is central phase compensation at the receiving station, option two is phase compensation at the receiving station supplemented with phase compensation at subscriber stations and option three is a local phase compensation at subscriber stations. The investment calculation shows that the second option: Central phase compensation supplemented with phase compensation at subscriber stations is the most favourable to implement.

It has previously been found that, during certain times of the year, there has been a low load on some of the transformers of the receiving stations. It has never been investigated if it is profitable to turn off one of the transformer for the entire, or part of the year.

In the investigation of the operation control of the transformers at the receiving stations, three alternatives have been considered. One alternative is that one transformer is in idle operation without load, the second alternative is that one transformer is completely turned off. The third alternative is to make no change. The study showed that the preferred alternative is to make no change, because the risks of turning off transformers are greater than the economic gain, that is approximately 101000 SEK.

The man – made climate impact have a negative effect on the environment and the society needs to make changes to be able to decrease the carbon dioxide emissions. Transportation is a big part of these emissions and new types of vehicles are crucial for a climate adaption, electric cars is one of these. Electric vehicles need infrastructure that enables charging of the cars, primarily in adherence to the home. This is a relatively easy process if the land where the vehicle is parked is owned by the same person who owns the vehicle. In residential areas, however, where the vehicle owner does not own the land where the vehicle is parked problems can occur when legal proceedings can hinder an establishment.

For a housing cooperative that want to install charging stations there are certain juridical aspects that must be considered. Housing cooperatives are regulated in Bostadsrättslag(1991:614) and there is an equality principle that has to be followed. The reason behind the principle is that all members of an association shall be treated equally, if no objective reasons say otherwise. The installation of charging stations in a housing cooperative is an expensive investment which only benefits one or a few residents that own an electric car. Therefore, it may be contrary to the principle of equality.

The purpose of the degree project has been to study how housing cooperatives at this moment can install charging stations and what the major difficulties are during the installation.

The method that has been used is a qualitative study with three participating housing cooperatives that have been interviewed with the focus of investigating how they dealt with charging stations and what they see as the key difficulties. The study showed that the installation of charging stations in cooperative housing was very difficult, mostly due to the problem of the principle of equality.

The result of the study showed that housing cooperatives used different methods to establish charging stations that relate to the principle of equality. The greatest difficulty with the establishment showed to be related to the financing, two different types of methods seemed to be the most usual. One method was the residents who were interested in charging an electric car funded the installation of the charging systems. Thru this method the housing cooperative did not have to fund the installation thus the charging stations was funded by the users. The second and most usual method was that the housing cooperative funded the charging station and thereafter took out a higher parking fee for the parking spots having charging capability. This worked as a pay-off for the housing cooperative and had the added benefit that the residents didn´t have to fund the initial installation off the charging stations.