Study On The Inhibition Of High-Speed Railway Harmonic Resonance

Along with the application of AC-DC-AC type electric locomotives, the traction power supply system fault occurs frequently because of the higher harmonic resonance, harmonic resonance has become one of the main factors affecting the safe and reliable operation of high speed railway.This paper through the analysis of locomotive harmonic output characteristics, resonant characteristics of the traction power supply system and the interaction between the locomotive and traction network, summarizes the law of traction power supply system harmonic resonance; through resonance sensitivity studies on the traction power supply system components, the harmonic suppression scheme which based on the structural parameters optimization design of traction power supply system are summarized, and with the actual circuit as an example, summarizes the inhibitory process and verifies the inhibitory effect.Paper establishes the harmonic model of traction substations and traction grid; taking locomotive CRH2type locomotive as an example, studies harmonic output characteristic when changes take place in rated conditions, power and supply voltage; using realistic circuit for physical prototype, frequency spectrum analysis method is used to study the traction substations’harmonic resonant characteristics such as resonant frequency, harmonic current and voltage amplification; comprehensively studies the influence on traction power supply system resonant characteristics caused by the locomotive and the impact on locomotive harmonic output characteristic caused by the traction grid. On this basis, the traction power supply system harmonic resonance rules are summarized.Based on the modal theory, the resonance sensitivity of the traction power supply system components are analyzed, with actual line as an example, paper research the resonance sensitivity of the traction power supply system components such as the Parallel components, Traction network distributed capacitance and Traction net wire impedance. According to the results, such measures can be used to optimize the structure of traction power supply system parameters and adjust the resonance frequency of the system as transformer equipment selection, choose electric split-phase installation position and Installation of compensation capacitors; combined with the traction power supply system harmonic resonance rule, paper puts a harmonic resonance suppression scheme.In the end, paper sums up inhibition process for newly laid lines and existing lines, optimize the realistic circuits respectively, comparison verified the effect of the harmonic resonance suppression scheme.