Reasearch on radiated interference from diesel locomotive traction motor to cab signalling

With the railway advancement of speed and load capacity, new high-power diesel locomotives occupy a prominent position. Due to the susceptibility of onboard signal equipment comprised of microelectronic devices, the diesel locomotive's traction motor (TM) may produce serious disturbance to cab signalling, possibly distorting the signal pattern via receiving coils, even resulting in mutation and decoding error of cab signals. However, the existing research studies pay little attention to this electromagnetic interference problem. This paper studies the radiated alternating magnetic field of the TM and interference coupling path to onboard equipment. It first analyses the cab signalling working principle and clarifies the interference mechanism, focussing on the quantitative analysis of the radiated magnetic field and interference electromotive force. Then, based on the ANSYS platform, the finite element method is used to complete modelling, simulation, and verification. Finally, combined with the railway field data, a typical interference case is analysed, verifying that the distorted signal pulses under the radiated magnetic field are the primary cause of decoding failures. This research establishes the quantitative relationship between the traction radiation intensity and the interference amplitude on signals, helping explore the countermeasures, improve the cab signal decoding accuracy, and ensure transportation efficiency.