Research on Synthesis Control of Power Quality for Electrified Railway

This paper analyzes necessity of synthesis control of power quality aiming at characteristics of traction power supply system for electrified railway. According to the fact that the existing power quality control, the measure and means were introduced, analyzed and compared in detailed. From reliability, technology and economy point, the project of synthesis Control was put forward on power quality of electrified railway in the paper. In order to achieve realtime detection and compensation for power quality of electrified railway traction power system, this paper provides a detection method of selective harmonic current, so vertiginous harmonic current of traction load is detected. Synchronously vertiginous passive power is gained basing on hilbert digital phase-shifting filter. And imbalance load current is balanced through regulating magnetron static VAR compensator (SVC) device. The kind new injectiontype hybrid active power filter (HAPF) combined with magnetron SVC make to compensate reactive power effectively, eliminate harmonic drastically and balance load imbalance current availably, and improve reliability and security of electrified railway greatly. Index Terms-electric railway, traffic safety, harmonic suppression, power quality, passive power compensation, negative sequence current