Electromagnetic interference assessment of a train–network–pipeline coupling system based on a harmonic transmission model

Abstract

Abstract The harmonics and resonance of traction power supply systems (TPSSs) aggravate the electromagnetic interference (EMI) to adjacent metallic pipelines (MPs), which has aroused widespread concern. In this paper, an evaluation method on pipeline interference voltage under harmonic induction is presented. The results show that the Carson integral formula is more accurate in calculating the mutual impedance at higher frequencies. Then, an integrated train–network–pipeline model is established to estimate the influences of harmonic distortion and resonance on an MP. It is revealed that the higher the harmonic current distortion rate of the traction load, the larger the interference voltage on an MP. Particularly, the interference voltage is amplified up to 7 times when the TPSS resonates, which is worthy of attention. In addition, the parameters that affect the variation and sensitivity of the interference voltage are studied, namely, the pipeline coating material, locomotive position, and soil resistivity, indicating that soil resistivity and 3PE (3-layer polyethylene) anticorrosive coating are more sensitive to harmonic induction. Field test results show that the harmonic distortion can make the interference voltage more serious, and the protective measures are optimized.

Keywords

• Induced voltage
• Inductive coupling
• Conductive coupling
• Harmonic resonance
• Electromagnetic interference