Sensorless Control of a High-Speed PMSM with Rapid Acceleration for Air Compressors using a High-order Extended State Observer

This paper proposes a position sensorless control strategy for high-speed permanent magnet synchronous motor (HSPMSM) used in air compressors. In the high-speed range, low ratio of carrier frequency to fundamental frequency will bring great trouble to the stability and performance of the drive system. In this paper, a discrete-time extended state observer (ESO) that considering the pulse-width-modulation (PWM) effect and computational delay is developed for back electromotive force (EMF) estimation. Meanwhile, the current control is ready with the information from the ESO and no additional PI current controller is required. Then, a high-order ESO-based phase-locked loop (PLL) is designed for higher estimation accuracy under rapid acceleration. The speed control is also integrated with the ESO-base PLL and a compact controller structure is realized. Simulations and experiments are performed on a 60000rpm PMSM to verify the effectiveness of the proposed method.