Efficient Partial Shading Detection for Photovoltaic Generation Systems

Maximum Power Point Tracking (MPPT) is the core technology for harvesting maximum power from Photovoltaic Power Generation Systems (PVGS). Global MPPT (GMPPT) algorithms have been broadly proposed in the past few years for PVGSs under Partial Shading (PS); however, most of these algorithms make the speed of MPPT slower and consequently lead to more tracking losses when there is no PS. Therefore, an efficient PS Detection (PSD) for PVGSs is proposed in the paper. The proposed PSD estimates the solar irradiance and temperature of a PVGS by the characteristic output function and measured voltages and currents. The occurrence of PS can then be detected by the estimated solar irradiance and temperature along with the proposed PS factor. After the PS condition of a PVGS was determined, the appropriate MPPTs can be chosen to track the MPP effectively and efficiently. This can accelerate MPPT performance, reduce tracking time, and improve power generation efficiency. Simulation results show that the detection accuracy of the proposed PSD can exceed 99% under different PS and temperature conditions. Experimental results demonstrate the validity and performance of the proposed PSD for PVGSs.