Current Sensorless Drive System of Synchronous Motor with Low-resolution Position Sensor

Abstract

The high-performance drives of synchronous motors such as a permanent magnet synchronous motor and a synchronous reluctance motor can be achieved by the current vector control. In such drive system, the armature current is controlled as a sinusoidal waveform based on the rotor position information from a high-resolution position sensor and the current vector (d and q-axis currents) is suitably controlled by the current feedback control.This paper proposes the current sensorless drive system with a low-resolution position sensor in order to simplify the SM drive system. The high-performance current control is achieved in the proposed drive system, where the current sensors are eliminated and the simulated currents are used for current control. The low-resolution position sensor is used instead of a conventional high-resolution position sensor, and the higher position information is estimated. The steady-state and transient characteristics are examined by the several experiments with respect to the synchronous reluctance motor and the interior permanent magnet synchronous motor. It is confirmed that the sinusoidal current drive, the high-performance current vector control and the speed control can be achieved by the proposed drive system.