High-Frequency Harmonic Resonance Suppression in High-Speed Railway Through Single-Phase Traction Converter With LCL Filter

High-frequency harmonic resonance has been a frequently encountered issue in railway traction power-supply system (TPSS), since high-speed trains that are equipped with ac-dc-ac traction drive system were serviced in China high-speed railway (HSR) lines. This high-frequency harmonic resonance is excited when the frequency of harmonic components introduced by the grid-side traction ac-dc converter in trains matches the inherent resonance frequency of TPSS. Traditional solutions for this HSR high-frequency resonance focus on providing damping to the TPSS. In this paper, with a focus on avoiding the resonance excitation, a solution from the trains' perspective through the adoption of a single-phase grid-side pulsewidth-modulated converter with an LCL filter in high-speed trains is proposed. Compared with the traditional traction system topology with an L-type filter, the total inductance value of an LCL filter is designed to be the same with that of an L-type filter and there is only an additional small capacitor adopted in the proposed solution. Therefore, the design in this paper meets the space and weight requirements of the traction converter system. In this paper, an all-parallel 27.5-kV 50-Hz autotransformer-fed power-supply system and the proposed grid-side LCL filter-based converters are modeled and simulated in real-time hardware in loop experimental platform. The results show that the proposed solution can effectively suppress the high-frequency resonance of TPSS.