The standard traction voltage in the railway system is 25kV, which is usually described as 27.5kV. At the same time, due to the characteristics of locomotive traction system, two single-phase 27.5kV power supply areas will be fed out from the traction substation. Harmonic and voltage fluctuation will be caused during locomotive operation. It is recommended to solve this problem by AC-DC-AC purification power supply, including the purification mode from 27.5kV to 10kV or from 27.5kV to 0.22kV/0.4kV. The field application scenario shall be selected according to actual needs. The core key power supply section in the railway system also includes a 10kV through line (35kV for individual through lines). Similar to the station 10kV, this system has the problem of reactive power. Nowadays, it is the main application scenario to transform the previous reactor or magnetically controlled reactor.

Case: Beijing-Tianjin Intercity Yizhuang Hub, Fengtai-Shacheng Railway Line, Shenyang Hub of Beijing-Shenyang Passenger Dedicated Line and Baotou-Xi'an Railway Line.

The station 0.4kV LV distribution system in the railway system is similar to that of general buildings. Due to the relevant characteristics of station equipment, there will be problems of the power factor and harmonic current in the system. According to industry experience, capacitive reactance compensation devices, intelligent hybrid compensation devices, active filter devices, static reactive power compensation SVG devices, active power quality comprehensive compensation devices, etc. are generally used, which are combined according to the size of on-site load and equipment operation experience. For example, APF + capacitive reactance; APF + intelligent hybrid compensation device; active power quality integrated compensation device; APF + SVG. The first three types are the mainstream configurations.

Cases: Shenyang North Railway Station, Baoding Railway Station, Chifeng Hub, Shaoguan Comprehensive Passenger Transport Hub of Wuhan-Guangzhou Passenger Dedicated Line, Emei Maintenance Base of Chengdu Railway Burea