Based On The Photovoltaic Grid Three-phase Inverter In High Frequency Loop Of The Research And Implementation

As the traditional energy especially the fossil energy depletion, and the hugeglobal incremental requirement of the energy resource, make the human society have tofind a reasonable energy mix, the sustainable energy which is low-carbon andlow-emission is the best choice. Photovoltaic effect is the direct use of the solar ray toget electricity, as the development of the power electronics and control theory whichapplied to this field, the photovoltaic system research rapidly developed worldwide.This paper is mainly based on the study and implementation of the10KW highfrequency DC-link grid connected inverter to research the key technology of the gridconnected PV inverters. The main circuit topology is high frequency pulse DC link andthree phase half bridge. In fact the High frequency pulse DC link circuit equal to theisolated forward DCDC converter, which duty circle is extended and could worked onthe duty circle greater than0.5. This structure with the next stage which driven byoptimized SVPWM could implement the combined ZVS function. The improvement ofthe efficiency, power density and reliability of PV inverters are systematic work. Thispaper will discuss the method to reduce the power switch on and off behavior to reducethe loss caused by power semiconductor to improve the PV inverter’s efficiency. Thehigh frequency transformer used in the PV inverter to reduce the volume and raise thepower density of the PV inverter. The gird connected PV inverter synchronous with thegrid is a key function, this paper proposed a Decoupled Double Synchronous ReferencePhase Loop Lock to implement this function. The system controller use TMS320F2812to implement the control strategy. The main circuit simulated on the PLECS standalone.The PV inverter witch this paper researched on got a significant improvementin efficiency and power density after the analysis theoretically and experimentalidentification.