Compensation algorithms for sliding mode observers in sensorless control of IPMSMs

Electromechanical sensors are commonly used to obtain rotor position/speed for high-performance control of interior permanent magnet synchronous machines (IPMSMs) in vehicle systems. However, the use of these sensors increases the cost, size, weight, wiring complexity and reduces the mechanical robustness of IPMSM drive systems. These issues, together with some practical requirements, e.g., wide speed range, extreme environment temperature, and adverse loading conditions, make a sensorless control scheme desirable. This paper proposes an extended back electromotive force (EMF)-based sliding mode rotor position observer for sensorless vector control of IPMSMs. Based on filter characteristics, a robust compensation algorithm is developed to improve the performance of the sliding-mode observer (SMO). Multistage-filter and dual-filter schemes are designed to further improve the steady-state and transient performance, respectively, of the compensation algorithms. The proposed SMO and compensation algorithms are validated by simulations in MATLAB Simulink as well as experiments on a practical IPMSM drive system.