A Novel Vector Magnetic Circuit Based Position Observer for IPMSM Drives Using High-Frequency Signal Injection

The accuracy of mathematical model of interior permanent magnet synchronous motors (IPMSMs) is of great importance for high-performance position sensorless control. However, the eddy-current reaction has not been modeled accurately in existing position sensorless control, in particular for the high-frequency (HF) voltage signal injection based position sensorless control. In this article, a novel HF signal injection based position sensorless control method is proposed for IPMSMs under the low-speed region. The key is to design a new HF position observation model of IPMSM with the vector magnetic circuit. By incorporating the magductance in magnetic circuit, the eddy-current reaction can be taken into account effectively in the proposed HF position observation model for IPMSMs. On this basis, the perturbation items due to eddy-current reaction in HF position observer are revealed and compensated to improve the accuracy of position estimation. Finally, the proposed HF signal injection based position sensorless control strategy is verified by experiments on an IPMSM drive platform.