High Precision Model Predictive Power Control Method for Battery Energy-Stored Quasi Z-Source Inverter

The battery energy-stored quasi Z-source inverter (BES-qZSI) is widely used for photovoltaic power generation system to suppress the fluctuation in photovoltaic power. With the model predictive control, the photovoltaic power generation system obtains a good performance in dynamic response. However, the control accuracy is affected by the sampling frequency because of one voltage vector applied very control cycle. In this article, a high precision model predictive power control method is proposed for the BES-qZSI to reduce the power fluctuation from the perspective of reforming the quality of dc-side inductor current and output current. The deadbeat control is modified to control the inductor current, so that the inductor current can track its reference command precisely with lower ripple. The dual-vector model predictive control is applied by expanding the voltage vector combination. The voltage vector inverter with higher phase freedom degree is applied to inverter, improving the control accuracy of the output current. The experimental results verify the validity and the advantages of the proposed method.