Research On Multilevel Inverter Topology Optimization And Simulation

With the fast development of Power Electronics, Micro Electronic Technique, Computer Technology and Modern Control Theory, The Multilevel Inverters have got large attention in Power electronical industry and the applications of the high powered A. C motors' motion control. In the region of low voltage and power, all the aspects of Power Electronics have drived to maturity stage, the objectives in the future will be high power density, high efficiency and high performance, and in the applications of high power electricity transmission and distribution, the technology of all aspects have been the priority research spots.With the advantages of large output capacity , being suitable for high voltage applications and low voltage/current harmonic, novel Multilevel Inverters have been widely used in middle voltage (1KV-10KV), high power(200KW-20MW) appplications , high voltage motion control, and the reactive power compensation of FACTS. In order to got better frequency spectrum characteristics, obtaining higher quality waves with less devices have been a new development direction.With the advantages of low output THD, low device voltage stress and low EMI, Multilevel Inverters have been a research hotspots of high voltage and large power applications. However, almost all the existing multilevel inverters have some disadvantages which limite their applications. Also, with the increasing number of output levels, the circuit topology and control method become more complex , then the system's reliability may be lower. In order to lessen the number of flying capacitors and clamping diodes, we offer a novel multilevel inverters topology with no clamping diodes and flying capacitors. In this topology, only two power devices of one phase sustain double voltage level, the other sustain the DC link capacitor voltage. The validaty is proved by PSpice8.0 simulation results. Based on the study of Multilevel Inverters topology structure and operating principle, this paper discussed both the advantages and disadvantages of these tree kinds of Multilevel Inverters, and attempt to find a kind of optimal topology by the use of Multiple Objective Optimization Theory and Genetic Algorithm.