Abstract: Objective: In rail vehicle operation, there is often electromagnetic interference from the vehicle mounted converter system with the BTM (Balise Transmission Module) antenna, resulting in its malfunction. It is necessary to identify the causes of the electromagnetic interference to develop interference suppressing measures. Method: By locating the interference source, the vehicle mounted converter system is identified as the root cause. The mechanism and transmission path of electromagnetic interference generated by the converter system is explained, and the impact of common\|mode interference and differential\|mode interference generated by the converter system on the operation of the BTM antenna is preliminarily analyzed. Then, a simplified circuit model and theoretical calculation formula are established, and the parameter range of adding components is provided. Three schemes for suppressing common\|mode interference and differential\|mode interference from the converter system are proposed, the external port amplitudes of these three schemes are tested. Result &Conclusion: By increasing the flow paths of common\|mode interference and differential\|mode interference signals, the internal circulation of interference signals within the converter system is achieved, reducing conducted interference to external devices of the converter system. The third scheme can effectively solve the interference problem with the BTM antenna.