Research on the Characteristics and Monitoring Methods of 27.5 kV Bus Voltage in Traction Substation

Research purposes: The 27.5 kV bus voltage of electrified railway traction substation is an important parameter of the power supply capacity and protection setting. Progressive failure of 27. 5 kV bus voltage transformer often occurs in actual operation. But the existing bus voltage monitoring measures can not detect the progressive fault in time, which eventually leads to the protection action outlet tripping and the power loss of the whole bus, expanding the scope of the accident. It is necessary to study the characteristics and monitoring methods of 27. 5 kV bus voltage in traction substation.Research conclusions: (1) The 27.5 kV bus voltage of traction substation is mainly affected by the capacity of traction transformer and system short-circuit capacity, of which the system short-circuit capacity has a greater impact.(2) The 27. 5 kV bus voltage of high-speed railway traction substation has the characteristics of high no-load voltage and limited fluctuation range. The fluctuation range is basically between 24 ~ 29 kV from maximum load to no-load.(3) The monitoring method of 27. 5 kV bus voltage value low alarm function and bus voltage transformer voltage difference high alarm function is proposed for electrified railway. (4) The research results in this paper can provide reference for identifying the bus voltage anomaly as soon as possible and ensuring the normal operation of traction substation. © 2023 Editorial Department of Journal of Railway Engineering Society. All rights reserved.