A design of common mode EMI filter for on board high power equipment of train traction system

As one of the typical interference sources, high-power equipment in train traction system will produce certain electromagnetic interference to signal equipment and other weak current systems.Therefore, it is of great significance to carry out research on common mode interference suppression technology of on-board high-power equipment of train traction system, to study a filter device which can be used to suppress common mode interference of high-power equipment in train and vehicle system, reduce electromagnetic interference caused by train traction system, and solve electromagnetic interference problems in actual vehicle operation process. Aiming at the serious electromagnetic conducted interference caused by the output of train traction system to traction motor, this paper analyzes the characteristics of common mode noise generated by traction system and the requirements of EMC national standards. Based on the theoretical basis of design of EMI passive common mode filter and the actual power level required, the frequency band and insertion loss of the filter are analyzed,According to two common mode inductors in traditional passive EMI filter, a three-dimensional structure is studied, and a common mode EMI filter which can be used in high-power equipment of train traction system is designed.