Soft switched notching current source inverters

An improved soft switched current source converter structure is reported. An evolution of possible forms is presented, and the operation of the circuit is explained. A simulation study illustrates the quality of closed-loop modulation in synthesizing a three-phase sinusoidal voltage under the soft switching constraints. An evaluation of the loss mechanisms in this structure is performed, and the relative loss terms are compared for a particular high-power thyristor. The primary disadvantage of the circuit is the voltage stresses, which are appreciably higher than line-to-line voltage but are roughly the same as that of current proposed soft switched CSI systems