Multilevel Inverter Based On X-shaped Inductor Networks

Because of the significant advantages such as low switching frequency、low stress of the components and low harmonics, multilevel inverters have been widely studied and used in many industrial application. However, research on current source multilevel inverter is less. Current source multilevel inverter is easy to realize four quadrant operation, it has a strong current limiting capability without short circuit protection. The energy storage device is inductance; it has longer service life. Currently most of the current source multilevel inverter has only boost ability with a few species and those affected the development and applications of the current source multilevel inverter.In view of the above problems, a family of multilevel inverter based on the active X shaped inductor network is presented in this paper. The proposed multilevel inverters have the characteristics of current-source inverter, while maintaining the basic characteristics of original converters; The structures have the ability of self-equilibrating current; The topology has the advantages of simple structure with low cost; it has a strong universality, a family of voltage source multilevel inverter based on the X shaped capacitor network can be derived using the duality theorem, those enrich the construction method of multilevel inverter. Carrier wave modulate PWM and space vector modulation method are used, Constant voltage control and constant current control are respectively realized by double closeloop control.According to theoretical analysis and the simulation results, the five level Buck-Boost inverter and the seven level Buck-Boost inverter prototype are designed and built. The experimental results are the same with the theoretical analysis and the simulation results, and in this way, the feasibility of the topology is verified.