Current-Source Double DC-Side Forced Commutated Inverter

DC-side commutated inverters are very attractive due to their simplicity and efficient use of the commutation circuit. A new current-source commutated inverter of this type equally applicable to both single and multiphase bridge configurations is considered. Simultaneous turn-off of all bridge thyristors allows ample possibilities for programming the commutation sequence. The behavior of a threephase bridge is analized, and the optimum values of the commutation components are obtained. Guidelines for analysis under any commutation condition, as well as general programming rules and suggestions for snubber design are given. Results obtained in a 8-kVA variable speed drive prototype are shown and discussed.