Improved Virtual Flux-Direct Power Control for PWM Rectifier Based on Second-Order Generalized Integrators

The AC-DC conversion system in the power system use generally 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 is widely used in many applications such as electrical drives and renewable energy conversion systems. It offers plenty of advantages, mainly 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. The different proposed approaches have been investigated through simulation using MATLAB/Simulink software.