Auto-tuning fuzzy PD control scheme for output voltage control of three-phase Z-source inverter

This paper proposes an auto-tuning fuzzy PD controller to control the output voltage of a three-phase Z-source inverter (ZSI). The proposed scheme adjusts the proportional and differential coefficients (Kp and Kd) in real time in order to find the most suitable Kp and Kd for PD controller and to simplify the controller design. The proposed scheme is verified the validity by co-simulation in PSIM and MATLAB/SIMULINK under the disturbance condition of both load step change and input DC voltage variation in Z-source inverter, and has compared with the conventional PID control scheme. The simulation results involve the comparison of three-phase output voltage, Z-network capacitor voltage and dc-link peak value which can directly reflect the three-phase output voltage quality. By those analysis and comparison, the availability of the proposed method in output voltage quality improving has been verified. Compared with conventional PID method, the proposed method showed a more effective and robust control performance for coping with the severe disturbance conditions.