Research On Coordinated Control Of Photovoltaic System

With the energy crisis and upsurges of environment protection, solar photovoltaicgeneration, as a kink of clean and pollution-free renewable resource, has aroused more andmore people’s attention. Based on research of stand-alone photovoltaic power generationcoordinated control system, this paper puts forward a new control method——impedanceadaptation method (IAM). Based on adaptive control of equivalent impedance,photovoltaic can obtain a continuous power output as required. Compared with thetraditional control method, IAM eliminates switching logic judgment of working modeand achieves maximum power point tracking (MPPT)and load power point tracking(LPPT)with one kind of control structure.First of all, the research status of photovoltaic coordinated control system at homeand abroad is analyzed. It makes a description of the equivalent circuit model and thesimulation of output characteristics about photovoltaic, and the supercapacitor in energystorage component is also introduced.Secondly, in the paper, it has described the working principle of IAM in detail, andintroduced its application in photovoltaic coordinated control system, the impact ofimpedance adaptation factor K is also analyzed. In order to maximize the use of solarenergy, optimize the design of impedance adaptation factor K. through the integration ofthe different intensity satisfies the impedance relationship matching or adaptation, thephotovoltaic battery output power as more as possible.Then, the working mode of coordinated control system was analyzed. according tothe control requirement, the control strategies of unidirectional converter and bi-directionconverter is designed differently. Since there are two converters in the system, in order toreduce the mutual interference between each other, the stability of the system is analyzed,and has designed a control scheme that make bi-direction converter as main control.Finally, the experiment platform has been builded, the main hardware circuit andcontrol process of coordinated control system also have been designed. By means ofsimulation and experiment, verify the proposed method is effective and feasible.