Performance and analysis for improvement of power quality and voltage sag mitigation

Aiming further to reduce its switching losses, an appropriate discontinuous modulation scheme is proposed and studied here in detail to doubly ensure that maxi-mal reduction of commutations is achieved. With an appropriately designed control scheme had incorporated with nine-switch converter is shown to favorably raise the overall power quality and voltage mitigation hence justifying its role as a power conditioner at a reduced semiconductor cost. A nineswitch power converter having two sets of out-put terminals was recently proposed in addition of the traditional backto-back power converter that uses 12 switches in total. The nine-switch converter had already been proven to have certain advantages, in addition to its component saving topological features. Despite these advantages, the nine-switch converter has so requiring an oversized dc-link capacitor, limited amplitude sharing, and constrained phase shift between its two sets of output terminals. Instead of accepting these tradeoffs as limitations, a nine-switch power conditioner is proposed here that virtually ―converts‖ most of these topological shortfalls are overcome into interesting performance advantages.