Sensorless control with time delay compensation for ultra-high-speed air compressor motors in fuel cell systems

Abstract

This study discusses the compensation of time delays in ultra-high-speed applications. Sensorless controls are used to estimate the rotor speed and angle. In model-based sensorless control, the voltage and current signals are used for angle estimation as an input of the observer. A time delay occurs when calculating these signals. Especially in the high-speed operating range, these time delays degrade sensorless control performance. This study proposes a method to compensate for these time delays, which improves accurate angle estimation. The proposed time delay implementation method has been validated through simulations and experiments using a 15 kW, 150 kr/min surface mounted permanent magnet synchronous motor for high-speed air compressors of fuel cell systems, where the ratio of switching frequency to fundamental frequency was 8:1.