The Leakage Current Supression Of Single Phase Current Source Inverter

The current source inverter has the capability of boost, and with a large DC inductance in its DC side, it also have a function of short circuit protection.With a long lifetime, the current source inverter is well suited as a photovoltaic inverter. When the current source inverter is applied in the non-isolated photovoltaic system, it will raise the issue of leakage current. In this paper, a single phase current source inverter and its application in non-isolated PV system is studied. And the method of its modulation is improved, then we can get a better ourput waveform quality.This paper analyzes the basic working principle of single phase current source inverter, moreover, the equivalent circuit model of the common mode is build and the factors affecting the leakage current are analyzed. The root causes of leakage current in the non-isolated system are revealed. On the basis of the above analysis, two single phase current source inverters with leakage current suppression capability are proposed in this paper. We name it current source H5 inverter and current source H6 inverter. The theoretical analysis is verified by simulation.Based on the in-depth study of the traditional SPWM control technology, this paper proposes a method based on the area equivalent principle. This nonlinear modulation method can guarantee the quality of output voltage with a smaller energy storage inductance.On the basis of theoretical analysis and simulation research. In this paper, the hardware design of the traditional single phase current source inverter and the new current source inverter is proposed. And on this basis, design and built a test prototype. The correctness of the theoretical analysis and the feasibility of the control scheme are verified by experiments.