The WRHE-PWM Strategy With Minimized THD to Suppress High-Frequency Resonance Instability in Railway Traction Power Supply System

Aiming at the high-frequency resonance instability phenomenon in high-speed railways and traction network (simplified as “train-network”) system, a new modulation strategy is proposed. It is the windowed resonant harmonic elimination pulse width modulation with minimized THD (WT-PWM). This modulation strategy can not only eliminate the harmonics around the resonant frequency in the train-network system but also combine the THD minimization target to reduce the risk of high-frequency resonance instability to the greatest extent. The modulation strategy can suppress high-frequency harmonics generated by the PWM switches of the network-side converter in a train fundamentally, thereby suppressing the high-frequency resonance instability caused by the train, which is regarded as harmonic sources. Finally, the effectiveness of the WT-PWM strategy is verified by real-time simulation and semi-physical simulation experiments.