A quiet position sensorless control for an IPMSM based on Extended EMF and Voltage injection Synchronized with PWM Carrier

This paper presents a new sensorless control method that does not generate acoustic noises for interior permanent magnet synchronous motors (IPMSMs). The magnetic pole position estimation is based on the extended EMF and the voltage injection synchronized with a PWM carrier. The carrier frequency is set high at 15 kHz, where we have difficulty to hear in order to remove the acoustic noise. The noise reduction strategies are proposed in two ways: One is a high carrier frequency sensorless control with a SiC inverter having a small dead-time (0.2 μs) switching devices, the other is a high carrier frequency sensorless control with a new dead-time compensation in addition to the voltage command value based on a polarity of the phase current and whether the PWM carrier is top or bottom. This compensates the effects of the dead-time without deteriorating symmetry of PWM pulse voltages. Effectiveness of high carrier frequency operations are verified by experimental results.