The Study On Control Strategy Of Grid-connected PV Inverters

Grid-connected photovoltaic (PV) generation has become the important part of the development and study on the energy. This paper discusses the basic theory and operation characteristics of the grid-connected PV 3 levels inverters, proposes neutral-point potential (NPP) balancing closed loop control method based on injection of zero-sequence voltage, which can retrain fluctuation in the neutral-point-potential effectively. PV Output Sensorless (POS) Maximum Power Point Tracking (MPPT) method is proposed based on the study on the control strategy of grid-connected inverters. Then this paper builds the simulation mode which can realize MPPT control and decoupling of active and reactive power, in order that PV system can send maximum active power and zero reactive power into grid. This paper takes much effort in hardware design of grid-connected inverter and program of control strategy with TMS320F2812, which can run in the hardwre system.