Improved-Reduced Order Generalized Integrator Based Sliding-Mode Observer for Interior Permanent Magnet Synchronous Motor Sensorless Control

The inverter nonlinearity, flux spatial harmonics and motor parameter mismatches give rise to the harmonics and dc offset in the back electromotive force (EMF) obtained by sliding mode observer (SMO), which will cause harmonic error in position estimation. So a SMO adopting improved reduced order generalized integrator (IROGI) is proposed to eliminate the dc offset and harmonics in the estimated EMF. The proposed method can converges fast under good performance of disturbance attenuation. A frequency-locked loop (FLL) is used to ensure frequency adaptive of the IROGI. The effectiveness of the proposed method has been verified by Matlab/Simulink simulation results.