Sensorless Control of Matrix Converter-Fed Synchronous Reluctance Motors Based on Direct Flux Vector Control Method

Abstract

A Sensorless control technique based on direct flux vector control scheme is proposed for matrix converter-fed synchronous reluctance motor drives. The amplitude of stator flux and current component quadrature to stator flux are closed loop controlled in constant switching frequency. A hybrid current-voltage model based flux observer is used so that at low speeds stator flux is estimated through current-to-flux maps and at high speeds, flux estimation is based on back-electromotive force integration. Moreover, a hybrid position and speed observer is proposed in order to estimate rotor position in a wide speed range. At low speeds and also in standstill, rotor position is retrieved based on high-frequency signal injection while at high speeds, back-EMF based model is used to estimate the rotor position. Also, matrix converter is modulated based on indirect space vector modulation. Simulation results for a 2.2 kW synchronous reluctance motor are presented to show the effectiveness of proposed sensorless drive.