Conduction Interference Suppression Method for MC-WPT System Based on Balanced Impedance

Suppressing electromagnetic interference (EMI) to improve electromagnetic compatibility is an urgent problem that must be solved in the application of magnetic-coupled wireless power transfer systems. This paper takes the traditional LCC-S type magnetic coupled wireless power transfer (MC-WPT) system as the research object. A fusion topology of EMI filters and harmonic compensation networks was proposed aiming at conducted interference caused by impedance imbalance and parasitic parameters. This paper analyzes the generation mechanism and transmission channel characteristics of conduction interference in traditional MC-WPT systems, provides a parameter design method for fusion topology, and verifies the effectiveness of the proposed topology in EMI suppression through experiments. On the constructed 85 kHz/500 W experimental system, the common mode interference current of the topology designed in this paper is reduced by 35.6 dB compared to the traditional LCC-S topology, and the differential mode interference current at specific frequency points is reduced by 23.6 dB. The common mode and differential mode conducted interference on the input side have been reduced by approximately 30 dB and 10 dB, respectively. The fusion topology and its design method proposed in this paper can also be applied to other MC-WPT systems with different resonant networks.