A simple and effective solution for superior performance in two-level four-leg voltage source inverters: Predictive voltage control

In this paper predictive voltage control strategy is proposed to control the output voltage of a three phase four-leg inverter. The four-leg inverter is developed to deliver power to three-phase loads under light, heavy, balanced and unbalanced load and source conditions and it can produce three output voltages independently with one additional leg. To predict the voltage behavior for each valid switching state, discrete model of the converter and load is developed. The control method chooses a state with minimum error between the output voltages and their references. The performance of the proposed predictive voltage control scheme is compared with carrier-based PWM method which is an equivalent to the symmetrically aligned-class I 3-D SVPWM. The feasibility of the proposed method is verified by MATLAB/Simulink. These results show that the proposed method has good performance and the capacity to compensate disturbances compared to classical methods.