Predictive direct power control with virtual-flux estimation of three-phase PWM rectifiers under nonideal grid voltages

In this paper, a robust virtual-flux (VF) based predictive direct power control (PDPC) (VF-PDPC) of a three-phase pulse-width modulation (PWM) rectifier is introduced. A simple neural filter based integrator (NF-I) is used for VF estimation. The NF-I leads to remove harmonic distortions and dc offset in the estimated VF components. The estimated VF components are used for robust sensorless VF-PDPC with a constant switching frequency. Numerical simulations are carried out for testing the proposal. Simulation results proved superiority of the proposed sensorless VF-PDPC compared with the conventional PDPC and PDPC based on the extended pq theory under unbalanced and distorted grid conditions. Better stability and quasi-sinusoidal grid currents have been achieved with the developed method under nonideal grid conditions.