IMPLEMENTATION OF A SENSORLESS INTERIOR PERMANENT MAGNET SYNCHRONOUS MOTOR DRIVE SYSTEM

摘要

This paper proposes a novel extended flux estimating method for an interior permanent magnet synchronous motor. By using the proposed method, an extended flux can be systematically derived. Then, the shaft position and speed of the motor can be obtained. To achieve starting from a standstill and a low-speed range control, a current-slope estimating method is used to replace the extended flux method because the estimating extended flux decreases as the motor speed is reduced. By combining the extended flux and the current-slope estimating methods, the interior permanent magnet synchronous motor drive system can be controlled in a wide range with satisfactory performance. The proposed system provides an adjustable speed range from 1 r/min to 2000 r/min and performs fast transient responses and good load disturbance responses. Moreover, a sensor-less position control system has been well-developed based on the speed control drive system. A TMS 320LF2407 digital signal processor is used to execute the rotor position estimation, rotor speed estimation, current-loop control, speed-loop control, and position-loop control algorithms. The hardware circuit, therefore, is very simple. Several experimental results are provided to validate the theoretical analysis.