Research On Solar Photovoltaic Inverter Controller

Photovoltaic(PV) power generation is the ideal alternative to fossil fuels,however, the higher cost of photovoltaic power than conventional powerrestricts its application. PV power inverter is a device in which DC output ofPV cells can be converted to AC electricity, and in the process of energyconversion and utilization, a large amount of energy is lost, which increasedthe cost of power generation. Therefore, the research of topological structureand control method of high-efficiency PV power inverters has significanttheoretical significance and application value.Based on the simulation of the engineered mathematical model of the PVcells, the power output characteristics of PV cells was studied; a new variablestep size method based on (dP/dV)/P was proposed after the analysis of theprinciple and stability of variable step size method based on dP/dV, and avariable step size control strategy with three kinds of step size was designedand the determination method its parameters was shown out; after the analysisof the advantages and disadvantages of different categories of topologies ofPV inverters, the control method and circuit parameters of2KW single-phasePV inverter was designed, the power utilization and control effect of outputvoltage of the inverter was analyzed in the simulation model built in MATLAB/Simulink.The simulation results show that the control effect of the modifiedvariable step size MPPT method was independent of the impact of lightintensity of PV cells, the strategy with three step sizes accelerated the speed ofthe MPPT of PV cells, and enhanced the steady-state output power; the PVinverter with multidroped parallel structure avoided the power loss when themismatch happened between the parallel components of PV cells, maximizedthe use of the output power of PV cells, and its output voltage had smallsteady-state error and fast dynamic response, so this structure and controlmethods of inverters provided a new way of PV power generation and urbanbuilding integrated applications...