Application of Digital Current Selective Tripping Protection in Subway Medium Voltage Ring Network Power Supply
Journal Title: Urban Mass Transit - Year 2024, Vol 27, Issue 10
Abstract
Objective Compared with traditional protection mechanism of medium-voltage ring network in power supply system, digital current selective tripping protection has quicker motion performance and better selectivity. However, while providing the possibility of infinite extension of protection range by selective tripping, the impact of cable capacitance current gets prominent and becomes a factor that cannot be ignored. Therefore, it is necessary to conduct in-depth research on digital current selective tripping protection and its setting design under the large partition of medium voltage network in subway power supply system. Method In view of the fact that digital current selective tripping protection is widely adopted by many urban rail power supply systems in China, a specific protection tripping case of Guangzhou Metro is selected to analyze in detail the waveform data recorded by the protection device, and further analyze the root causes of tripping phenomena in and out the fault zone. Result & Conclusion The wave recording data in the fault zone exhibits typical single-phase grounding fault characteristics, which is consistent with the actual cable fault situation. However, outside the fault zone, the distortion of the current waveform is shown to be caused by the sudden change of voltage. Due to the basic balance of the three-phase load in subway 33 kV ring network, and in the case of phase C voltage loss, although the voltage of phases A and B experiences a brief distortion (about 3 cycles), the change in load current during this period can be ignored. Therefore, the distortion of the three-phase current is mainly caused by the capacitance current of the cable. In view of this situation, the setting design principle of the digital current selective tripping protection should be improved in a timely manner.
Authors and Affiliations
Muran ZHANG
Keywords
Related Articles
- EP ID EP749251
- DOI 10.16037/j.1007-869x.2024.10.048
- Views 40
- Downloads 0
Research on the Application of E-CNY Boarding Code in Urban Rail Transit
［Objective］ As in China E-CNY (hereinafter referred to as "digital currency") flourishes in all walks of life, the application scenarios of digital currency in urban rail transit are gradually enriched. Traditionally,...
Simulation Analysis of Electromagnetic Interference Effects of AC Traction Metro Tunnels on Oil and Gas Pipelines
［Objective］ Currently, several cities in China are planning 25 kV AC (alternating current) power supply metro lines, inevitably there will be paralled sections of oillgas pipelines run parallel to metro tunnels. During...
Passing Performance of Inverted T-shaped Frog Turnouts for Suspended Monorail Vehicles
[Objective] The suspended monorail transportation system holds promising prospects, yet researches on the dynamics performance of vehicle passing through turnouts remain relatively scarce, requiring comparison for furthe...
Gauge Deterioration Prediction of Urban Rail Transit Lines Based on CEEMD and SVR
［Objective］ In order to strengthen the status ma-nagement of urban rail transit line sections, it is necessary to predict the overall deterioration trend of the gauge in space. ［Method］ CEEMD (complementary ensemble...
Spatial Function Optimization of Transfer Station with Different Waiting and Security Check Modes under Integrated Operation of Intercity Railway and Metro
Objective There exist some differences between intercity railway stations and metro stations in operational management rules and mechanisms. In order to achieve smooth transfer, function integration, advanced application...