Abstract
This paper develops a 5kW permanent-magnet synchronous generator (PMSG) drive applied to a flywheel energy storage system (FESS). Since the PMSG is generally operated at high and medium speed range in the FESS, the extended EMF method is suitable. The system configuration including the current control algorithm, position sensorless scheme and hardware circuit design is introduced. The model and parameter estimation are performed for the design of current control and position sensorless control schemes. The derivation of the space-vector based current control and extended-EMF position sensorless control is accomplished. The position estimation and current control are implemented by the microcontroller. First, the estimation accuracy of the rotor speed and position is verified. Next, the performance of the proposed current control is validated by the measured current waveforms. Finally, the output voltage regulation under load variation and output power control under speed variation are achieved by the proposed voltage and power controllers.