Circuit–Field Cosimulation for Predicting Internal Transient EMI and Optimizing EMC in Electric Locomotives During Neutral Section Passage

Transient electromagnetic interferences (EMI) occurred within electric locomotives during the neutral sections passing process can cause abnormal functioning of internal electronics systems, posing significant risks to safe and stable operation of locomotives. This paper establishes a circuit-field co-simulation model to predict and analyze the transient electromagnetic environment inside locomotives during neutral sections transitions, achieved by performing transient simulations of circuit topologies encompassing traction power supply system and electric locomotive high-voltage system and providing transient interference source excitation for full-wave electromagnetic environment simulation within locomotives through circuit simulation. The accuracy of the proposed model has been validated through practical measurements, enabling the quantification of transient EMI levels and their frequency-domain characteristics during this process. Furthermore, the influence factors on in-cabin transient EMI levels has been systematically investigated, revealing breaker’s switching phase angle and arc reignition characteristics are the key parameters determination the interference level, providing critical insights for optimizing electromagnetic compatibility design in electric locomotives.