Deadbeat Predictive Power Control with Fuzzy PI Compound Controller and Power Predictive Corrector for PWM Rectifier Under Unbalanced Grid Conditions

Under unbalanced grid conditions, the DC side voltage of pulse width modulation (PWM) rectifier will overshoot during start-up and reference voltage transients, which may lead to system instability. In this paper, a deadbeat predictive power control (DPPC) with fuzzy PI compound controller (FPCC) and power predictive corrector (PPC) is proposed to solve that problem. Firstly, the parameters of the PI controller are adjusted online by the fuzzy control rule of the FPCC to eliminate the overshoot of the DC side voltage and contribute to faster dynamic responses, which thereby could correct the reference active power. Secondly, the static error between the reference and system active powers is reduced by accumulative predictive errors in the PPC. The simulation is carried out under ideal and unbalanced grid conditions. The result shows that the proposed control scheme can effectively eliminate the overshoot of DC voltage, reduce the static error of active power, and improve the dynamic response and anti-interference ability of the rectifier.