A modified capacitor voltage control algorithm for suppressing the effect of measurement noise on grid-connected Z-source inverters controllers

Abstract

Inverters are considered the orbit of research objectives for safe and reliable grid interface. Amongst the conventional inverters known as suitable candidates for gird connection in the last two decades, Z-source inverter (ZSI) emerged with buck/boost voltage capabilities compared to the counterpart voltage source inverter (VSI) and current source inverter (CSI). Therefore, ZSI introduces the merit of single stage grid interfacing of DG especially with renewable energy sources. Proper control of key parameters in single stage grid interface is essential. In the ZSI operation, the capacitor voltage is the most vital key parameter which can be controlled throughout the boosting factor. In this paper, the conventional capacitor voltage control is modified to enhance the performance of grid-connected ZSI and increase its immunity against the measurement noise. The proposed modification is verified throughout simulation. Furthermore, the experimental results obtained from a grid-connected ZSI prototype substantiate the proposed improvement.