Role of ZigZag Transformer on Neutral Current Reduction in Three Phase Four Wire Power Distribution System

Natural characteristics of alternating current with high harmonic content and the overloaded neutral wire caused by the non linear loading of electronic power supplies, electronic ballasts, UPS systems, adjustable speed drives become one of the most popular and very complex topic among electrical engineers. There are different solutions are offered for this problems by researchers such as zigzag transformers, active filters, L-C tuned filters etc. The triplen harmonic components injection to neutral is predominantly increasing due to rapid usage of power electronics devices with three phase four wire system. The neutral current and neutral voltage in three phase four wire system, particularly supplying to sensitive measurement and control system loads is a big concern nowadays. This paper conceives the role of zigzag transformer for the reduction of neutral current caused by triplen harmonics feeding by the non linear loads like UPS systems. The role of zigzag transformer on neutral current reduction caused by the triplen harmonics has been investigated with non linear loads. The result shows the zigzag transformer contribute effectively towards reduction of neutral current in three phase four wire distribution power systems.