Reactive Power Compensation Scheme for Urban Rail Power Supply System Considering Main Substation Resource Sharing

Abstract

[Objective] The resource sharing among main substations in urban rail transit power supply system can lead to significant cost savings. In this context, it is essential to investigate reactive power compensation schemes for different phases of main substation resource sharing to ensure that the power factor at the PCC (point of common coupling) meets the standards. [Method] Taking the power supply system of a city's metro line as example, based on the train schedule and power supply system structure, the minimum reactive power compensation required at PCC before and after main substation resource sharing under daily power factor compliance is calculated. A reactive power compensation setting scheme considering main substation resource sharing is proposed, based on the minimum reactive power compensation that meets the compensation requirements before and after main substation resource sharing, with the goal to minimize SVG (static var generators) capacity, determining the installation capacity of SVG and reactor or capacitator. [Result & Conclusion] In the power supply system of the case study line, the actual configuration of the reactive power compensation devices for the 1# main substation main transformer power supply zone is as follows: reactor capacity is 6.0 Mvar, and SVG capacity is 1.0 Mvar. For the 2# main transformer power supply zone, the configuration is a reactor capacity of 3.0 Mvar and an SVG capacity of 0.5 Mvar. The proposed reactive power compensation scheme replaces a total capacity of 9.0 Mvar SVG devices with reactors, meeting the reactive power compensation requirements while reducing investment costs.

Keywords

• urban rail transit
• main substation resource sharing
• reactive power compensation strategy