Motor controller

A motor controller for an electric vehicle including a battery, a converter circuit that boosts a DC power obtained from the battery, an inverter circuit that converts the DC power obtained from the converter circuit into an AC power, a smoothing capacitor provided between the converter circuit and the inverter circuit, and a motor driven by the AC power obtained from the inverter circuit, the motor controller configured to control a drive of the motor by controlling an operation of the inverter circuit,

• wherein a resonance region is an operating region of the motor that causes a resonance of an LC circuit configured by a reactor of the converter circuit and the smoothing capacitor, and
• wherein the motor controller is programmed to permit execution of square-wave control of the motor only within a predetermined time period in a case where the converter circuit is not boosting the DC power and an operating point of the motor is included in the resonance region and the motor controller is programmed to prohibit execution of square-wave control of the motor when outside of the predetermined time period in the case where the converter circuit is not boosting the DC power and the operating point of the motor is included in the resonance region,
• wherein the predetermined time period is shorter than an amount of time needed to overheat the converter circuit or to deteriorate the battery by the resonance of the LC circuit.