A Position-Sensorless IPM Motor Drive System Using a Detection Circuit of Current Variations

This paper proposes a new circuit configuration for a position-sensorless drive system using an interior permanent magnet synchronous motor (IPM motor) rated at 3.7kW. The configuration can decrease the number of the sample and hold circuits to four, though fourteen sample and hold circuits are required for the conventional system. In addition, the configuration makes it efficient to detect current variations. It is shown experimentally that the drive system has good position estimation characteristics with absolute and relative errors within ±2 deg and ±0.5 deg in electrical angle, respectively. Moreover, the position control response is improved by adding current control loops to the position-sensorless drive system.