A Study on the Application of a 3-Phase 4-Wire Zig-Zag Filter in a 100kW Electric Vehicle Fast Charger

This study proposes a 3-phase 4-wire zigzag filter that is applicable to a 100 kW electric vehicle (EV) fast charger. The 30 kW class four power converter linked in parallel results in a current imbalance at the input terminal, leading to a sharp, unbalanced current at the neutral point of a 100 kW high-capacity rapid charging apparatus. Moreover, owing to increased harmonic noise, decreased power factor, increased reactive power, decreased active power, decreased efficiency, and electromagnetic wave generation, the unbalanced current at the neutral point is a primary cause of EV charger failures. This study proposes an ideal 3-phase 4-wire zigzag filter for a 100 kW EV fast charger and experimentally verifies that it lowers the neutral point unbalanced current, eliminating harmonics and reaching a peak efficiency of 95.632%.