Research Of Single Phase Grid-connected Photovoltaic Generation System

The rapid development speed of the world’s economy has made the situation of the poor energy much worse; the fossil resources such as the coal, oil and gas have been less and less, so that all countries are developing new energy now. Solar energy as one of the Earth’s most abundant clean energy has been a great concern of the society. Traditional type of photovoltaic power generation system uses a large number of series-parallel PV modules to make up an array, the central inverter does the inverter work on PV array centralized, and then the AC power will be transferred to the grid. However this method has some disadvantages such as high DC voltage, low efficiency, and single point of failure problem; the distributed photovoltaic power generation system can solve the above problems.Distributed photovoltaic power generation system is a small-power system, lots of stand-alone power generation systems connect to the grid. Single phase photovoltaic power generation system consists of PV array, inverter, filter and protection devices. The photovoltaic array is used to convert solar energy into DC energy; the inverter converter DC power to AC power energy; the filter smooth the output current; the protection devices protect the key components of the system to make sure the system work well.This paper first analyzes the background and current situation of the development of the single-phase grid-connected PV systems. Then the principle and characteristics of the PV array is introduced. The structure of the single-phase photovoltaic power generation system and current control strategy are introduced in detail. Then the key technologies in the single-phase photovoltaic power generation system such as the maximum power point tracking, phase-locked loop technology, islanding detection technology are introduced, a DSP-based single-phase photovoltaic power generation system is designed. At last, the system is modeled and simulated by Matlab tools.On based of the simulation models, some power generation simulation experiments are executed. The result of simulation is record and analyzed and it has proved that the simulation models with a high simulation speed and the result is correct. The simulation can reflect the working process of the inverter completely.