An Improved Optimization-Based Sensorless Scheme for Interior Permanent Magnet Synchronous Motors

This paper presents an improved optimization-based sensorless scheme (IOBSS) for permanent magnet synchronous motors to enhance estimation accuracy and resistance to noise of the conventional schemes. By optimizing over multiple time steps simultaneously, the measurement data of currents and voltages are utilized more effectively. After taking the mechanical dynamics into account, a new cost function is designed, which enables the previously indistinguishable local minima to be distinguished. Compared to the conventional method, the proposed method significantly improves the immunity against measurement noise and reduces the dependence on precise initial estimations. The effectiveness of the IOBSS is validated through simulations under noise and step-change conditions.