A Current Supported PV Array Reconfiguration Technique to Mitigate Partial Shading

Abstract

Partial shading in a solar PV plant is an important concern as it reduces the output power. Dynamic array reconfiguration (DAR) helps in reducing the impact of partial shading. But, it has its own limitations. Further, DAR does not guarantee single peak in array power-voltage characteristics during partial shading. It requires sophisticated and costly MPPT controller to track the global peak in order to extract maximum power from the PV array. In this paper, an improved DAR strategy is proposed using current injection (CI). This CI-based DAR strategy enhances the array power output beyond what is achievable by the available DAR techniques. Using this technique, multiple peaks in the power-voltage characteristics of the PV array are also avoided. The proposed method is evaluated for different levels of shading and its patterns. Experimental results establish the superiority of the CI-based DAR method over the available PV array reconfiguration strategies.