Maxmum Power Point Tracking Of PV Syetem Under Partially Shaded Condition

Partially shaded conditions and non-uniform solar irradiance are common in all kindsof PV systems. The mismatch phenomenon such as partial shade not only affects thepower generated by solar system, but also leads to security and reliability problem. Still,under partially shaded conditions, the P-V curve of PV array sometimes shows multi-localmaximum, which makes the maximum power point tracking very difficult to accomplish.At present, there are two main aspects to solve photovoltaic array mismatch problem. Oneis to seek the new algorithm which has the ability to search the real MPP (MaximumPower Point), the other is using distributed PV architectures providing means to alleviatemismatch phenomenon.By understanding and analyzing the basic principle of solar cells, the P-V curve ofmulti-summit under partial shading, a novel strategy of MPPT (Maximum Power PointTracking) named pseudo-power fitting is introduced, which is mainly regarding totraditional series-connected PV arrays.By analyzing distributed PV array architectures, the advantages of distributed MPPTand the selection of DC-DC converter are given. When a boost converter is employed todistributed MPPT, this paper analyzes the range of solar radiation in order to maximize theoutput power of each PV panel.At last, the effectiveness of the algorithm and the validity of theory analysis areexamined using the Matlab/Simulink.The hardware circuit of the control system withman-made partially shaded condition is also constructed through the use of DSP. Theeffectiveness and preciseness of the MPPT system is proved by the results of theexperiments.