Research On The Three-phase Current Source Inverter Based On The X-shape Inductance Network

In recent years, due to environmental problems, the development of wind power,photovoltaic power generation and a series of renewable energy are promoted, but the use of these new energy cannot do without grid connected inverter. The traditional voltage source inverter has buck capability, which the boost DC links need to be added. And the current source inverter itself has boost capability, without intermediate boost link. But the new energy generation system,s output voltage is fluctuating badly because of environment influence. In view of the above problems, this paper the three phase current source inverter based on the X-shape inductance network is researched, which can implement the buck/boost convert.On the basis of a large number of periodical literature both at home and abroad,compares the current three-phase current source inverter topology, this paper found a new method which can boost and buck, inverter bus current can reach twice the inductance current of three phase current source inverter based on the X-shape inductance network.Compared with the current Buck-Boost three-phase current source inverter for this topology, in ensuring the boost and buck capacity, without increasing the number of switching devices, the current transmission gain is higher. First, this paper analyzes the working principle of this topology, and the SPWM modulation strategy with the least number of switching times is designed, which reduces the switching loss; the boost and buck performance is studied, the mathematical relationship between DC input voltage and the AC output phase voltage of fundamental amplitude is derived about modulation ratio m. Secondly, in order to realize the bidirectional flow of energy, a double current loop structure with direct current control is designed. Finally, in order to apply it to the SMES interface converter, the power close loop control based on instantaneous power theory is designed, and the four quadrant operation is realized.In this paper, the above theoretical analysis is verified by the MATLAB simulation software, and on this basis, a three phase current source inverter based on the X-shape inductance network experimental platform is built, the correctness and feasibility of thetheoretical analysis are verified by the analysis of the experimental results and the simulation results.