Critical evaluation and review of partial shading mitigation methods for grid-connected pv system using hardware solutions: the module-level and array-level approaches

Abstract

This paper reviews and evaluates the hardware solutions to mitigate the effect of partial shading for grid-connected photovoltaic (PV) system. It encompasses both the module-level as well as the array-level approaches. The former enhances the energy yield by maximizing the power extraction capability of each individual module. Here, three methods, namely the micro inverter, the power optimizer and the energy recovery circuit are covered. On the other hand, the array-level mitigation—which includes the dynamic and static array reconfigurations optimize the arrangement of the modules to minimize the effect of partial shading on the energy yield. Besides updating the important aspects of the technologies, this paper delves into the economic viability of the solutions, as well as the challenges and future trend. In addition, it benchmarks the performance of the module-level solutions with the system with string inverter using Simulink. It is discovered that if the plant is highly shaded, the net energy gain of the micro-inverter and power optimizer is significant. On the other hand, if the shading is non-existent, employing these devices can be counterproductive (in terms of yield).