A Survey of Output Characteristics and Power Optimization Technology of Photovoltaic Array in Mismatch Scenario

Nowadays, the photovoltaic (PV) power generation technology using solar energy has been widely used. In the PV power generation system, the study on reliability covers the mismatch problem of PV array, namely the difference between the expected power output and the actual power output of PV array. In the actual application, problems such as internal aging, local shading, uneven irradiance and inter-module connection of PV array are all likely to cause the mismatch of output, resulting in reduced output power of PV array. Among them, the mismatch between PV array modules caused by local shading is the foremost factor leading to the mismatch of PV array. Therefore, in recent years, scholars at home and abroad have studied and explored various global maximum power points to solve the power multi-peak problem of photovoltaic arrays generated by the above local shadows, and achieved some remarkable results. In this paper, the mathematical model and output characteristics of PV array are introduced, the mismatch between PV array modules caused by local shading are analyzed and explained, and the optimization technology of PV array in the mismatch condition and the prospect of future research direction are summarized.