The Reasearch And Design Of100KW Three-phase Grid-connected PV Generation System

Mankind’s demand for electricity is increasing day and day, while the environmental pollution are also increasingly severe every day. This contradiction promotes the urgent needs of the new energy. The PV grid-connected system is a very important usage of new energy. This thesis is committed to the research and design of the100kW three-phase PV grid-connected system, considering the actual project needs. The thesis’s main work and innovation are as follow.For the inconsistency of photovoltaic (PV) cell in photovoltaic array of PV grid-connected system, a novel method of the PV inconsistency detection was proposed in this paper. The piecewise linear interpolation method and the least squares method are combined to calculate the inconsistency of PVs in the proposed method. Compared with the traditional maximum power distinguish method, the proposed method enhances the detect effect. Simulation results prove its validation. The simulation experiment results prove the proposed method of the piecewise linear interpolation method and least squares has better effect and accuracy than the maximum power distinguish method.For the problem of heat dissipation issues of the PV system, this paper introduced the principle of the dissipation, analyzed and caculated the power loss of the inverter. Besides,the paper made use of the basic thermodynamic model to get the100kW three-phase PV grid-connected system heat sink performance requirement. Follow this requirement,this paper fix the certain heat sink type. And finally, the result of the thermal simulation software verified that the heatsink design type meet the heat sink requirements of the100kW three-phase PV grid-connected system.On the base of analyzing kinds of main circuit topology type and grid-connection control method, this paper also designed the the main circuit in details, which contains the the main circuit realization, power device choosing, the Capacitance parameter and the grid-connected L;adapted the dual loop control; And finally PSIM simulation proved that the design and the control strategy is feasible.The paper also shows control system hardware and software design details. Major hardware circuit design included the whole design of the hardware plan, the the peripheral sampling circuit, the zero crossing capture circuit design and the communication circuit design; Software design included the software main program and the PC monitor design process. Finally, using all this designs we develop a prototype, and we make some test on it. This paper, for the inconsistency of photovoltaic (PV) cell in PV grid-connected system, proposed a novel method of the PV inconsistency detection, and for the problem of heat dissipation issues of the PV system, this paper collected the heat sink.While,considering the actual project needs,this paper also offerd the design of the main circuit and the hardware and the software of the control system. This thesis could offer the consultion and reference for the building of PV grid-connected systems for kinds of power levels.