The vehicle industry must reduce emissions to lessen their environmental impact. Using electric motors for propulsion and batteries for energy storage decreases the pollution and greenhouse gases emitted by heavy commercial vehicles such as trucks and buses. As they often travel long distances, a large energy storage is needed, and it needs to be possible to recharge it quickly. The fast recharging requires high power chargers with high voltage and high current, and that in turn necessitates a suitable overcurrent protection system to avoid damageif a fault would occur.

Possible technologies for this overcurrent protection system are investigated in this thesis, and the different solutions are evaluated based on important metrics. A solid state breaker is found to be a promising technology that limits the current quickly and reliably.

The evaluation including computer simulations shows that the technology is feasible, but some aspects of the circuit design need to be executed carefully like the inductance, the sampling frequency of the current measurement, and the design of the snubber circuit.