The Research Of Ac Module Photovoltaic Grid-connected Inverter

Solar power has become one of the most important renewable energy due to the energy crisis recently. Grid-connected application is the tendency of photovoltaic generation system. With the improvement of the solar battery and power electronics, the main research fields of the photovoltaic grid-connected power system focuses in higher power density and higher efficiency techniques. This situation increases the rigid requirement for the reliability and cost-dwon.Ac module system is an independent PV inversion system, which enjoys its unique safety , ecomonical and small -size feature over the traditional photovoltaic generation system .The AC module is promsing in the future use. This paper first summarizes the common topologies of ac module and their characteristics. A new voltage-type ac module is presented, the topology of the ac module is composed of a push-pull series resonance converter and a full-bridge grid-connected inverter, and then the operation of this inverter is analyzed. The math model of ac module is derived by using state space averaging method, then the derived model is used to conduct the controller design. A new maximum power point tracking(MPPT) strategy is introduced in this paper, it is desigened to follow the variations of solar panel insolation to achieve maximum power point tracking.In the end of this paper, 100W prototype of the voltage-type series resonance ac module system is designed and tested,the simulation results showes good performance thus validate the proposed scheme .