| Solar energy is widely used in recent years. In the whole world, the technique of Photovoltaic system is growing fleetly. Grid-connect inverter is one of the key to Photovoltaic system. For making the whole Photovoltaic generating system more flexible, reliable, and improve the quality of electricity, a new Z-Source inverter topology may be adopted in the system. Base on the analysis of Z-Source, the whole Photovoltaic generating system is researched.The main contents of this paper are: The analysis of Z-Source topology and operation principle. For different bus output specialty, there are two modes: Voltage Mode Z-Source Inverter-VMZSI and Current Mode Z-Source Inverter-CMZSI. The operation principles of the two modes are analyzed. Lastly, by the compare with the traditional inverter, the advantages and disadvantages are summarized. The analysis of Voltage Mode Z-Source Inverter using State-Space averaging method. Putting the non-linearity and time change equation to linearity equation, and getting the transfer functions. Analyzing and summarizing the maximum power point tracking(MPPT) control method and non-islanding protection. The perturb and observe algorithms and Incremental Conductance Algorithm are mainly introduced for the maximum power point tracking. Analyzing the control strategies of photovoltaic generating system based on Voltage Mode Z-Source Inverter. There are loop configurations for whole control system is built: the grid current loop, Z-Source capacitance voltage loop, and photovoltaic array output voltage loop. By the analysis of principles, the control adjustors have been designed through the root locus method. Designing the main circuit parameters for Voltage Mode Z-Source Inverter. The grid inductance is chosen by satisfying the speediness of current tracking and restraining the harmonic; the Z-Source Inverter capacitance is chosen by restraining the ripple; the photovoltaic array out filter capacitance is chosen by restraining the ripple.
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