TWO-STAGE FILTERED SLIDING MODE OBSERVER-BASED PERMANENT MAGNET SYNCHRONOUS GENERATOR SENSORLESS CONTROL

In the field of control systems for permanent magnet synchronous generators (PMSGs), a novel sensorless control approach employing a sliding mode observer (SMO) based on a two-stage filter structure is introduced. This method aims to address the inaccuracies in rotor position detection and speed assessment, typically associated with the chattering phenomena in conventional SMOs. Initially, the proposed SMO is developed utilising the mathematical model of the generator. Subsequently, in lieu of a standard low-pass filter (LPF), a variable frequency complex coefficient filter (VFCCF) is designed. This filter is adept at mitigating harmonic distortions in the back electromotive force (EMF), thereby circumventing the phase delay issues inherent in traditional LPFs. Furthermore, a modified back-EMF observer (MFBEMFO) is employed to attenuate the ripple component in the back EMF signal, resulting in a more refined output. Finally, the effectiveness of the proposed control strategy is substantiated through simulations conducted on the MATLAB/Simulink platform, providing a comprehensive evaluation of its performance.