Abstract：In recent years, multilevel inverters are becoming more and more popular in AC drive system. The diode clamped inverter has found wide applications in the medium and low voltage drives. But with the increase of the voltage degree and switch numbers, it’s difficult to keep the clamped capacitors’ voltages to be balanced. This paper presents a novel diode clamped five-level inverter topology, which introduces an independent dc-source to feed the inner loop DC-bus. With the optimization control method, the clamped capacitors’ voltages in the DC-link can be kept balance under full range of the load. Simulation and experimental results show the feasibility and validity of this new scheme. The proposed topology gives a new alternative of five-level inverter in motor drive applications.
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2010, Vol. 25 
