Power conversion device for electric vehicle

A power conversion device comprising:

• a main battery;
• an auxiliary battery that has a lower voltage than the main battery;
• a step-up converter circuit that is connected to the main battery, the step-up converter circuit being configured to step up a voltage of the main battery;
• an inverter circuit that is connected to the step-up converter circuit, the inverter circuit being configured to convert an output of the step-up converter circuit into an alternate current and output the alternate current to a motor for running of a vehicle;
• a high-voltage wiring that connects the step-up converter circuit and the inverter circuit to each other;
• a smoothing capacitor that is connected between a high-potential wire of the high-voltage wiring and a low-potential wire of the high-voltage wiring;
• a main wiring that connects the main battery and the step-up converter circuit to each other;
• a subsidiary wiring that is connected to the auxiliary battery;
• a DC-DC converter that is connected to a high-potential wire of the main wiring, a low-potential wire of the main wiring, a high-potential wire of the subsidiary wiring, a low-potential wire of the subsidiary wiring, the high-potential wire of the high-voltage wiring and the low-potential wire of the high-voltage wiring;
• a controller that is connected to the auxiliary battery and the DC-DC converter, the controller being configured to drive the inverter circuit, wherein
• the DC-DC converter is configured to supply a power stored in the smoothing capacitor to the controller through the DC-DC converter such that the controller drives the inverter circuit and that the power stored in the smoothing capacitor is supplied to the motor through the inverter circuit, when a collision of the vehicle is detected.