| ABSTRACT:With the reduction of the fossil energy and the pollution of the environment, the demand for the new and renewable energy is growing rapidly. More and more attention has been paid for the solar energy, which is one of the most important renewable energy, as its unique merits. Photovoltaic power generation is one of the most promising use of the solar energy. As the development of the photovoltaic power generation technology, people begin to research high-power PV grid generation.High-power PV grid system is mainly applied in desert photovoltaic power stations and large industrial parks, which can meet the demand of the local load. It can also take the power to the grid. In this paper, many topologies for the high-power PV grid system, for example the conventional topology, the topology of the distributed MPPT technology, the topology of group control technology system and the distributed PV power grid system, are deeply analyzed. Also, the grid converter is analyzed for the advantages and disadvantages of the various topology, applicability and performance etc.Through the comparison of the various topologies, one of the topologies is selected in high-power PV grid system, which has a better performance, higher efficiency, and more mature technology. Many detailed studies of this topology have been done in this paper. This system topology is based on the PWM bridge converter with the use of centralized MPPT control, single stage energy transformation, and the industrial frequency transformer. Based on the mathematical model of the photovoltaic array and the converter, the system control strategy is introduced, and the main parts for the converter are designed. The high-power PV grid system is modeled and simulated through the MATLAB. The photovoltaic array output characteristic is detailed analyzed as well as the MPPT control and the waveform of the grid. Finally, the experiments of the high-power PV grid system demonstrate the correctness of the research results.
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