Investigations on Single-Phasing Effect of Zigzag Autoconfigured Transformer Based 12-Pulse Rectifier

High power industrial loads are often fed from front-end multi-pulse rectifier as its ability to effectively and inexpensively mitigate the harmonics on the AC side is achieved by the multi-pulse autoconfigured transformer. This paper analyzes and investigates the operability of the zigzag autoconfigured transformer based 12-pulse rectifier when one of the input terminals is open, i.e., single-phasing. Contrary to the prior art multi-pulse rectifiers, the availability of neutral point in zigzag autoconfigured transformer results in normal operation at DC side during single-phasing. A detailed MATLAB Simulation is carried out to understand the single-phasing operation of the zigzag autoconfigured transformer. Further, the experimental results from the laboratory prototype are presented to validate the simulated results.