Patent ID: 9692351
Date: 2017-06-27
CPC Classifications: H02H,H02P

Claim:
1. A protective device for a vehicle inverter, which protects an inverter that drives a motor provided in a vehicle as a power source from overheating, comprising: a maximum element temperature calculation unit that calculates a maximum element temperature among respective element temperatures of the inverter; an element temperature output limit coefficient calculation unit that calculates an output limit value corresponding to the maximum element temperature, sets a current output limit value as a current output limit coefficient when the current output limit value is smaller than a preceding output limit coefficient, and sets, as the current output limit coefficient, a value obtained by adding a predetermined value determined in advance to the preceding output limit coefficient when the current output limit value equals or exceeds the preceding output limit coefficient; a basic torque limit value calculation unit that calculates a basic torque limit value from a map on the basis of a motor rotation speed of the motor; and a torque limit value determination unit that determines a torque limit value by multiplying the basic torque limit value by the element temperature output limit coefficient.