Study Of Photovoltaic (PV) Power Generation Technology Based On The New Z-source Inverter

With the continuous economic and social development in recent years, the energyand environmental problems is becoming increasingly serious. The development andutilization of new kinds of energy are paid more and more importance and the so-calledgreen solar energy is highly attracting our attention with its characteristics ofinexhaustible and pollution-free.So far the solar power technologies have been widelyresearched and studied, and the inverter, key component of the solar power system,plays a crucial role in the effective transformation and utilization of the electrical energy.The inverter has several shortcomings whether it is of traditional voltage type, currenttype, or Z source type which is relatively popular in recent years. To meet theshortcomings, a new type of Z source inverter was proposed and employed for thepower conversion unit of the photovoltaic power generation device to realize effectiveutilization of the solar energy and security interconnection with the power system in thisthesis.A photovoltaic power generation system with a new Z-source inverter wasanalyzed theoretically and designed practically based on the in-depth analysis of theapplication limitations of se’veral traditional inverters and the new Z-source invertersoperating principles.Firstly, the system solutions are analyzed and designed in detail tomake the PV array realize effective energy conversion of light and power safely throughthe new Z source inverter under the coordinated control of a DSP control unit.Then,because of the special boost/buck characteristics and performance requirements of thePV inverter in the Z-source network, the thesis shows the detailed software andhardware design, and the parameters of the power devices and software control processused in the system are also studied in detail. Finally, the system interference areanalyzed and the corresponding software and hardware anti-interference measures arecarried on.On the basis of the above theoretical analysis and design，a new Z-source PVinverter control platform with a DSP control unit was built, and the correctness of thetheoretical analysis and design is veriifed through the experimental results. The innovation points this thesis presents are these. On one hand, a new Z sourceinverter was employed as the power conversion unit without the DC voltagetransformation unit, thus simplifying the system design and saving the design cost aswell; on another, the improved drive circuit and MPPT control algorithm also make thesystem more safe and stable.