Electromagnetic interference characteristics and countermeasures on subway train

Electromagnetic compatibility between the running of subway train and exterior space is related to driving safety and stability. The countermeasures on the EMI characteristics are becoming main technique points. The EMI Test results of one subway train about 9k-1GHz show that EMI of 150k-1.15MHz exceed the limit. The DC input side of inverter is identified as the main EMI resource after studying and analyzing the EMI resources of the whole train and electromagnetic propagation path. The parameters of safety capacitor is confirmed by exceeding frequency and electrical parameters of inverter as well as main circuit configuration of the whole train. Field test data which meet standard requirement indicate that the safety capacitor optimize EMI of the whole train.