Study Of Grid-connected Pv Technology Based On The New Z-source Inverter

Nowadays, on account of the problems of environmental pollution and exhaustion of energy resources becoming worse and worse, exploring and using of new energy become more and more important. Solar energy is one of the most clean, practical and large scale regeneration energy resources. The whole world focuses on the use of photovoltaic (PV). The PV grid-connected system will be the main utilization of solar energy, so it will be developed rapidly. The inverter is the last or the only one power converter stage of grid-connected PV station, whose efficiency and reliability will influence the performance of the whole system. he traditional converter includes voltage source converter and current source converter . However, both of the converters have barriers and limitations. For making the whole PV generating system more flexible,reliable and improve the quality of electricity,a new Z-Source inverter topology is adopted in the system.In this paper, the operating principle and superiority of the new Z-source inverter are described firstly, And its mathematical model and PWM control strategy are analyzed in detail. Then the devices voltage and current stress is analyzed. Analyzing the control strategies of PV grid-connected system based on the new Z-source inverte.And the control adjustors have been designed through the root locus method.In order to validate the analysis conclude.Finally a set of new Z-source inverter systems is built under grid-connected PV system, the simulation and experimental results have been performed to confirm the analysis. They are quite consistent with the theoretical analysis.