Position sensorless control of a novel flywheel energy storage system

This paper presents a position-sensorless field-oriented control of a novel axial flux permanent magnet machine for flywheel energy storage system. The approach is based on the estimation of the motor induced voltage with the help of measured stator currents and reference voltages. Based on sliding mode observers, rotor position can be accurately estimated. This novel flywheel energy storage system is successfully controlled under position-sensorless scheme which eliminates the hassle of rotary encoder and reduces the system´s cost. Both simulation and experimental results are illustrated for verification.