Complex-Coefficient Synchronous Frequency Filter-Based Position Estimation Error Reduction for Sensorless IPMSM Drives
Xuan Wu, Xu Yu, Ting Wu, Kaiyuan Lu, Shoudao Huang, Hesong Cui, Shuangquan Fang
Abstract
Accurate rotor position is significant for the back electromotive force (EMF)-based sensorless interior permanent-magnet synchronous motor (IPMSM) control. However, the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">±</i> (6 h±1)th harmonics will appear obviously in the estimated back-EMF due to the effect of the inverter nonlinearity and flux spatial harmonics. These harmonics will subsequently result in the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">±</i> (6 h)th harmonic pulsation in the estimated rotor position. In order to deal with this issue, a new complex-coefficient synchronous frequency filter (CCSFF)-based sliding mode observer combined with a quadrature phase-locked loop (PLL) is proposed to mitigate the back-EMF voltage distortion. Therefore, the performance of the position estimation is remarkably improved. The proposed CCSFF possesses both bandpass-filtering and frequency-adaptability characteristics. It can pass the fundamental component without magnitude attenuation and phase delay in different frequency scenarios. Moreover, the linearized model of the proposed CCSFF-PLL-based position estimation system is established and a systematic parameter design is presented to obtain promising dynamic performance. The effectiveness and feasibility of the proposed method are confirmed by experiments on a 1.5-kW IPMSM test platform.