Research On Control Strategies Of Photovoltaic(PV) Grid Power System

Along with the global energy crisis has became serious increasingly, the development ofnew energy and application has payed more and more attention of the world. Photovoltaicpower as a sustainableand no pollution new energy, is an important part of global energy ofthe future. In recent years, photovoltaic (pv) grid power has became the mainstream of thephotovoltaic application. This paper’s main research object is photovoltaic (pv) grid powersystem control strategy, and this paper researched and analysed three core problem ofphotovoltaic (pv) grid power system detailedly and in depth. These three questions are: solarcell’s maximum power point tracking, photovoltaic (pv) grid power inverter’s control strategyand grid system island detection.First, this paper introduced the principle of photovoltaic cells power generation and thecharacteristic of the circuits, researched the principle of maximum power point tracking(MPPT). The effect of maximum power point tracking directly affect the work efficiency ofphotovoltaic (pv) grid system. This paper introduced and analysed several common MPPTmethods, and uses the incremental conductance algorithm to make modeling simulation andvalidation.Second, the paper studied several commonly used control methods of the photovoltaic(pv) grid power system. The system uses single stage three-phase grid structure, choosesrepeat-PI control as photovoltaic (pv) grid inverter control strategy, and uses the Space vectorpulse width modulation(SVPWM) technology output PWM waves, and put forwards a novelvariable step long phase lock method to realize phase lock.Third, the paper introduced the islanding of photovoltaic (pv) grid system, given theuniversal relative standard of island test, and analyzed several passive and active islandingdetection method, and used the active interference detection method which based on thepositive feedback to realize island test.Finally, set a model of MPPT and photovoltaic (pv) grid inverter in the Matlabenvironment, and analysed the simulation waveform.