Voltage Sensorless Direct Power Control for PWM Rectifier Under Distorted Network Using Improved Virtual Flux Estimator

Abstract

Generally, AC-DC conversion system in the power system use the diode-bridge based rectifiers that cannot be reversible and causes high current distortion. Besides, they reduce the power factor and energy quality. recently, the application of three-phase pulse width modulation (PWM) rectifier has been risen quickly due to breakthrough advancement in the power devices. This converter offers sinusoidal input currents and minimized harmonic distortion and unity power factor. This work presents an improved sensorless control for performance enhancement purpose of the PWM-rectifier. The proposed control strategy uses the virtual flux principle with second-order generalized integrator (SOGI) in order to overcome the accompanying drawbacks of using pure integrator of low-pass filters for estimation. The integration of improved virtual flux estimator with direct power control saves the cost of using many voltage sensors which can increase the reliability and effectivity of the control system. Moreover, it improves control robustness and against highly distorted network. The different proposed approaches have been investigated through simulation using MATLAB/Simulink software.