Real-Time Reduction of Rotor Position Estimation Error Based on the Stator Flux Estimation-Combined Method for Sensorless Control of PMSMs Drives

Abstract

This paper presents the implantation and the performance improvement of real-time reduction of rotor position estimation error based on the stator flux estimation-combined method for sensorless control of PMSMs drives. Wherein, the proposed method is designed based on a simple algorithm for accurate estimation and robust control of quasi-exact stator flux and position/speed of PMSMs. A large-speed range of applications in sensorless control strategies is achieved by using the mathematical model of PMSM motor. The latter presents the main idea of the estimators’ structures design. They are generally composed of voltage and current models (VM and CM). However, the dynamic performances of these methods are influenced in the low and high-speed ranges, and they are sensitive to parameters variations. The estimators’ structures are dominated by the current model at the low-speed range, and by the voltage model at the high-speed range. The technique proposed in this study is the combination of the two preceding models; this provides performances’ improvement in the PMSM dynamics for a large speed variation with compensating estimation errors for the two separate methods (VM and CM). The main objective of this combined method is the drawback reduction for the separate use of VM and CM estimators. The algorithm principle is based on exploiting and combining the two estimators while measuring the stator voltages and the currents, in addition to estimating the rotor position and the speed. Furthermore, the performances of the proposed method have been tested and validated through real-time experiments by using dSPACE ds 1104 DSP board.