An over-voltage protection circuit prevents an anomaly, such as a short circuit in the upper-switched electronic device of a DC-DC power supply, from propagating to downstream circuitry. For example, the fixed part is located in the upper part of the cowling, the mobile part being located in the lower part of the cowling. The system includes a hydrogen fuel cell array for receiving hydrogen from the fuel reformer. In some examples, the fuel source contains methane, syngas, or hydrogen gas, and the oxidizing agent contains oxygen gas, air, or oxygen enriched air.