| 摘要 |
PROBLEM TO BE SOLVED: To detect abnormality caused on a thermistor for measuring a coil temperature of a motor. SOLUTION: A coil temperature is estimated from a resistance value of a coil on a three-phase synchronous motor 40 and compared with a measured value by a thermistor 80. To estimate the coil temperature, first an electric angle is input from an angle detector 142, measuring voltage is applied with timing where predetermined phase voltage zero-crosses, and a current value corresponding to the measuring voltage is measured. In addition, inductance is obtained from the detected electric angle, coil resistance is obtained from the inductance value and the measured current value, and the coil temperature is estimated based on the coil resistance value. If an error between the estimated coil temperature and the coil temperature measured by the thermistor 80 exceeds a predetermined value, abnormality occurring in the thermistor 80 is determined. |
