Research for the effects of high-speed electrified railway traction load on power quality

High-speed electrified railway traction load will affect the power quality. To satisfy the request of rapid speed and high density traffic, the large and impactive traction power is necessary for trains running on the high-speed electrified railway. The traction load call for a power system with strong power supply capability, and its effects on power quality of the power system should not be ignored. A 220kV single-phase traction power supply system for the Wuhan-Guangzhou highspeed electrified railway section is introduced. On the basis of the traction power supply system´s actual operation situation, the impact performance of traction load and imbalance characteristic of load current are analyzed, and the ability of traction power supply system to withstand the traction load is also briefly evaluated. By installing power quality monitoring system in the substation supplying traction load directly, the actual operation data of this traction power supply system is obtained. The voltage and current characteristics is analyzed, and the effects of traction load on the power quality are evaluated using the related power quality indicators. The research shows that the most outstanding factor worsening power quality is the unbalance three phase current. Because the regional power network is always operating at a bus-splitting mode, the way integrating the single-phase traction transformers into different phases of the power grid to balance the system´s three-phase load can not achieve the desired result. The program and operation scheme for high-speed electrified railway power supply system introduced in this paper has a significance of being referenced and promoted, it can satisfy the reliability requirements of power grid operating and quality requirements of power supply.