Rail Transit Operation And Maintenance

Urban rail transit includes metro, light‑rail, high‑speed railway and intercity rail systems. As operating mileage keeps expanding, regular inspection and preventive maintenance for power supply, vehicle, track‑signalling and station systems are required by industry specifications. Aging cables, insulation deterioration, poor grounding, over‑heated connectors, partial discharge and power‑quality distortion may trigger equipment failure, service interruption and safety risks.

UNI‑T delivers a complete instrument‑oriented O&M solution for urban rail transit. It covers four core scenarios: power‑supply system, vehicle system, track‑signalling system, and station system. The solution supports acceptance inspection, daily patrol, periodic maintenance and fault troubleshooting, helping rail‑transit operators, depots and third‑party maintenance teams implement quantifiable, traceable field tests to guarantee safe, reliable operation of rail‑transit assets.

System Composition & Testing Logic

The whole rail‑transit operation chain consists of traction power‑supply substations, catenary pantograph systems, rolling stock vehicles, track & signalling equipment and station electrical facilities. The solution performs targeted measurement for typical failure points: ‑ Check insulation, leakage current and DC winding resistance for transformers, cables and high‑voltage equipment; ‑ Verify grounding & lightning‑protection resistance of substations, viaducts and station control cabinets; ‑ Evaluate backup battery health via internal‑resistance testing for DC/UPS power supplies; ‑ Locate hot‑spot overheating non‑intrusively with thermal imagers; ‑ Capture partial‑discharge defects using acoustic‑imaging cameras; ‑ Analyze harmonics, three‑phase unbalance and power‑factor for traction power networks.

Early‑stage hidden defects can be identified before major breakdowns occur, shifting maintenance from emergency repair to proactive risk prevention.

Four Core Testing Modules

1. Power‑Supply System Testing

‑ Test items: Insulation resistance, leakage current, transformer DC resistance, grounding resistance, battery internal resistance, thermal temperature screening, partial discharge detection, power‑quality analysis. ‑ Key instruments: UT513B insulation tester, UT251C+ leakage‑current clamp meter, UT575B ground‑resistance tester, UT620C+ micro‑ohmmeter, UT677C battery tester, UTi640J thermal imager, UT568B acoustic imager, UT285C power‑quality analyzer.

2. Vehicle System Testing

‑ Test items: On‑board motor insulation, depot lightning‑protection grounding, vehicle‑equipment leakage, bogie & circuit temperature monitoring, three‑phase current & harmonic analysis of on‑board air‑conditioning units. ‑ Key instruments: UT503PV insulation tester, UT278D ground‑resistance tester, UT251C+ leakage‑current clamp meter, UTi640J thermal imager, UT285C power‑quality analyzer.

3. Track & Signalling System Testing

‑ Test items: Power‑line & communication‑equipment insulation, protective‑grounding resistance of equipment rooms, UPS battery internal resistance, equipment temperature monitoring, signal‑system power‑quality inspection. ‑ Key instruments: UT503PV insulation tester, UT278D ground‑resistance tester, UT677C battery tester, UTi640J thermal imager, UT285C power‑quality analyzer.

4. Station System Testing

‑ Test items: Rail joint insulation, motor insulation for station fans, traction‑network & station lightning‑protection grounding resistance, track‑circuit current, rotating‑equipment vibration, low‑voltage‑distribution harmonic monitoring. ‑ Key instruments: UT503PV insulation tester, UT278D ground‑resistance tester, UT219PV AC/DC clamp meter, UT312A vibration tester, UT285C power‑quality analyzer.

Solution Value

1. Proactive risk prevention: Detect incipient faults including insulation degradation, bad grounding and partial discharge ahead of equipment breakdowns, reduce unexpected service outages.

2. Standardized quantifiable inspection: All test results can be stored, exported and reported, complying with official rail‑transit O&M regulatory requirements for inspection records.

3. Field‑adapted hardware: Portable, anti‑interference test instruments fit complex working conditions: traction substations, vehicle depots, tunnels, viaducts and station equipment rooms.

4. Full‑chain coverage: Covering power‑supply, rolling‑stock, track‑signalling and station facilities, to lower overall maintenance cost and improve operational safety for urban rail‑transit networks.