Effect of Single-Phasing on Multipulse Rectifier With Active Interphase Reactor

When one of the input terminals of multipulse rectifier (MPR) is open, MPR operates under single-phasing. This paper analyzes the effect of single-phasing on MPR with active interphase reactor (AIPR). The output voltages of phase shift transformer and the voltage across the secondary winding are calculated under single-phasing. Compared with the voltages under normal operation, the amplitude of ouput voltages are not equal to each other under single-phasing, and phase difference of arbitrary two phases are not equal to 120°. The MPR with AIPR is equivalent to two single-phase full-bridge rectifiers operating in parallel. Zero-phase difference of output voltages of the two bridge rectifiers leads to no harmonic power being absorbed by the AIPR. Some simulation and experiment are carried out to validate the theoretical analysis.