A novel isolated 36-pulse AC-DC converter for line current harmonic mitigation

Abstract

In this paper, a novel delta/tapped star transformer for 36-pulse AC-DC converter configuration is designed, modeled, simulated and developed to feed isolated DC varying loads. The proposed AC-DC converter is suitable for large current rating rectifiers such as electrowinning, electrochemical processes, induction heating, etc. Its main feature is its reduced kilovolt-ampere (kVA) rating. The circuit has been designed for retrofit applications, a delta/tapped star-connected transformer platform is also included in the converter. First, we have simulated the proposed scheme via Matlab/Simulink software supplying different load conditions. Then, it has been implemented based on the motivation we have gained throughout the simulation results. The results show significant improvement in power quality indices (according to the IEEE-519) at the point of connection to the utility. We achieve less than 4% of input current total harmonic distortion (THD) with our proposed configuration for supplying different load scenarios. Moreover, we achieve a satisfying power factor (almost unity) for DTCIMD operation. Also, a prototype of the proposed transformer-based 36-pulse ac–dc converter has been developed, and test results are presented to validate the developed design procedure and the simulation models of this ac–dc converter.