Reserch On Hybrid Photovoltaic-commercial Power System Based On Multiple Input Converter

The development of new energy has been getting more and more attentions for relieving the energy crisis and environment issue. But some new energy are discontinuous and unstable because they are limited by themselves and weather. In order to get a system which can work stably and continuously and optimize the use of the energy, multiple new energy are combined to form the hybrid new energy power system, which can take advantages of the characteristic of the new energy and the connections between them to make the most use of these new energy. In the hybrid new energy system, a multiple-input converter(MIC) is introduced to replace the several past single-input converters which can simplify the circuit and lower the cost.As a useless and clean new energy, solar energy has been researched by scholar all over the world. As a stable energy, commercial power is well suitable for making up the shortcoming which solar energy is strongly limited to the weather in the area can easily get commercial power.MIC is introduced from the concept of the hybrid power system in this paper. According to some connection rules, various kinds of MIC are created from the basic structure and formation unit. Taking double-input Buck converter for example, the basic theory and characteristic of this kind converter is analysed in this paper. Also, the power management strategy of the hybrid photovoltaic-commercial power system is introduced. This converter has a simple circuit and a flexible control method, and its two input sources can supply power at the same time.In order to distribute the power between the solar cell and gird appropriately, the characteristic of the two power should be learned. This paper presents the working principle and characteristic of the solar cell, and builds the mathematical model of the solar cell. The simulation model is also built in Matlab/Simulink to conbine with the commercial power to form simulation model of the hybrid system based on double-input Buck converter.It needs to conduct power management to the hybrid power system to realize the prior use of the solar cell. The main idea of the power management is to let the system work under three models which can let the load make the most use of solar cell and the commercial power make up the lacking power. This paper adopts two regulators, one makes the solar cell work under MPPT model, the other one makes the output voltage stable. At last, a 200 W hybrid photovoltaic-commercial power system based on double-input Buck converter is built to do the experiment. The result shows the correctness of the principle of the system and the rationality of the power management strategy.