Patent ID: 8712618

Claim:
A power conversion device for an electric vehicle, comprising: a power converter that drives an induction machine; and a control unit that controls the power converter, wherein the control unit includes a drive stopping unit, and the drive stopping unit includes a secondary-resistance-temperature detecting unit that detects temperature rise of a secondary resistance of the induction machine based on a slip angular frequency of the induction machine calculated based on a current detected by the induction machine and on a motor constant of the induction machine, speed information of the induction machine calculated based on the current, and speed information of an electric vehicle detected by an external-speed-information detecting unit, and a drive-stopping-signal output unit that includes a time element that detects that temperature rise of the secondary resistance continues for more than a predetermined time element by an output from the secondary-resistance-temperature detecting unit, and outputs a drive stopping signal for stopping a driving operation of the power converter based on an output from the time element and the speed information of the electric vehicle.