Control of a three-phase four-wire active filter operating with an open phase

This paper investigates the utilization of a power compensation control scheme that provides fault-tolerant operation for a three-phase four-wire system containing a shunt active power filter. With such a control strategy, when one of the filter converter legs is lost, the power compensation can still be provided partially with only two phases. A suitable pulse-width modulation control scheme is derived to be used for the after-fault operation. The system model after-fault condition is derived. Experimental results are presented to demonstrate the correctness of the proposed solution.