Research Of Bi-directional DC/AC Converter Based On Z-Source Network

The inverter based on Z-source Network is a new inverter, it has been the new topology which appeared in recent years. Because of its unique topology, it has many advantages which the traditional inverter does not have:the Input source can select not only the voltage source but also can choose the current source; the switch can not be damaged because of the shoot-through; No the output harmonic has be reduced because it has not the dead time inserted into the system; it allows the inverter circuit to select boost or buck based on the required, and so on. But the general Z-source inverter has a drawback:it can occur a non-work status of discontinuous current when the parameter selection is not the time. But the bi-directional DC/AC converter based on Z-source network can allow the energy to flow bi-directional. it is a good solution about this problem,and improves the stability of the system. This article has a research and design about the bi-directional DC/AC converter based on Z-source network.At first, the article describes some defects and shortcomings about the traditional inverter, which leads to the concept of Z-source inverter. And it describes the advantages of Z-source inverter, development status and application areas of it. And it detailed analyzes the working principle of the general Z-source inverter topology, analyzes the non-intermittent status of the Z-source inverter about discontinuous current, and gives solutions. On this basis, it analyzes the work mode of the bi-directional DC/AC converter based on Z-source network.Then, the article analyzes the two control modes of the Z-source inverter based on understanding its working principle, and highlights the through subsectional SVPWM control mode of the bi-directional Z-source inverter. And it gives the simulation model and results of the whole system in MATLAB/SIMULINK. And it designs the software and hardware respectively of the bi-directional Z-source inverter. In the hardware, it designs the main power circuit and control circuit. The detailed designed method about Z-sources network's capacitors and inductors has been given. Each device has be selected. And part of the circuit schematic has been given.In software, the article Highlights the generation Method about the SVPWM control waveform of Z-source inverter, and gives some of the software flow chart.Finally, this paper gives the simulation model and simulation results of the closed loop system, the simulation results show the advantages of this design.