Implementation of Sensorless Vector Control for Permanent Magnet Synchronous Motor Drive

Abstract

Typically, Permanent Magnet Synchronous Motors (PMSM) is used for high-performance motor drives and high-efficiency. Fast-performance motor control is characterized by soft rotation around the motor’s entire speed range, full zero-speed torque control, and quick acceleration or even deceleration. Vector control techniques for permanent magnet synchronous motors are used to achieve such control. Also commonly referred to as Field-Oriented Control (FOC) are vector control techniques. The vector control application’s basic idea is to decompose a stator current into a part producing a magnetic field and a part generating a torque. After decomposition, both components can be individually controlled. Senosorless Control of PMSM has occupied researchers since long time. The result of this work is becoming widely accepted by industry due to reliability, low cost and parameter independency. Sensorless velocity and location control of PMSM still is a challenge especially for surface mounted permanent magnet synchronous machine. This thesis describes the Saliency based method for control of surface mounted permanent magnet synchronous machine. Because the simple machine design is not used, this fails at low and zero speed. The observer tracks the saliency in the machine and calculates the speed and position based ion that. High frequency signals are injected into the stationary axis of the machine and the demodulation of the high frequency response current gives speed and position independent of the parameters of the machine. Such methods are therefore independent of machine parameters and can easily be adapted to various machines.