Compensation of Periodic Magnetic Saturation Effects for the High-Speed Sensorless Control of PMSM Driven by Inverter Output Power Control-based PFC Strategy

Abstract

An inverter output power control based power factor correction (PFC) strategy is being extensively used for permanent magnet synchronous motor (PMSM) drives in appliances because such a strategy can considerably reduce the cost and size of the inverter. In this strategy, PFC circuits are removed and large electrolytic DC-link capacitors are replaced with small film capacitors. In this application, the PMSM d-q axes currents are controlled to produce ripples, the frequency of which is twice that of the AC main voltage, to obtain a high power factor at the AC mains. This process indicates that the PMSM operates under periodic magnetic saturation conditions. This paper proposes a back electromotive-force (back-EMF) estimator for the high-speed sensorless control of PMSM operating under periodic magnetic saturation conditions. The transfer function of the back-EMF estimator is analyzed to examine the effect of the periodic magnetic saturation on the accuracy of the estimated rotor position. A simple compensation method for the estimated position errors caused by the periodic magnetic saturation is also proposed in this paper. The effectiveness of the proposed method is experimentally verified with the use of a PMSM drive for a vacuum cleaner centrifugal fan, wherein the maximum operating speed reaches 30,000 rpm.

A rotor initial position estimation method for sensorless field-oriented control of permanent magnet synchronous motor

“…The use of these sensors leads to the emergence of some problems, for example the cost of the sensor, increased equipment complexity and reduction of the mechanical robustness (Acarnley and Watson, 2006). Scientific research has evolved to solve these problems; a sensorless vector control technique has been developed for variable speed PMSM drives (Delpoux and Floquet, 2014; Lee, 2015; Yang et al, 2016), instead of using a rotor position sensor. Consequently, many methods for rotor position and speed estimation have been researched.…”