Research on Anti DC Bias and High Order Harmonics of Five Order Flux Observer for IPMSM Sensorless Drive

Due to the motor parameter mismatches, the errors of current sampling circuit, converter nonlinearities and noise, DC bias and high order harmonics exist in flux model, which make the traditional flux observer estimation inaccurate. In this paper, an interior permanent magnet synchronous motors (IPMSM) sensorless drive method based on a five order flux observer is proposed to suppress DC bias and high order harmonics. The proposed five order flux observer can completely remove DC bias and has strong filtering ability for high order harmonics. Additionally, the parameters of the five order flux observer are set through s-domain analysis. Then, the discrete five order flux observer is obtained to better implementation in digital systems, and the discrete five order flux observer is easy to implement. The proposed five order flux observer is verified by experiments on a 2.0-kW IPMSM drive platform.