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Case Study on the Application of Withdrawable Switchgear in Subways and High-Speed Railways

Release time:

2025-10-10

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Abstract

As the core equipment of low-voltage distribution systems, withdrawable switchgear demonstrates unique advantages in the rail transit sector thanks to its modular design, high reliability, and flexible maintenance features. This article analyzes its technical principles and application value through typical cases such as the Shanghai Metro, Guangzhou Metro, and Shenzhen High-Speed Railway.

1. Subway System: Comprehensive Integration from Power Distribution to Intelligent Operations and Maintenance

1. Shanghai Metro: Core Power Supply Hub for the Entire Line

Shanghai Metro's certain line utilizes Schneider Blokset withdrawable low-voltage switchgear as its power distribution center and motor control center, serving critical equipment such as ventilation systems, air conditioning units, elevators, and escalators. The switchgear features a three-zone isolation design—comprising the busbar section, functional unit area, and cable section—to ensure electrical safety. Additionally, its drawer units are equipped with high-precision ±0.1mm guides, guaranteeing that after 10,000 insertions and removals, the contact resistance remains stable below 50 μΩ. On the智能化 front, the system integrates a Profibus-DP bus interface, enabling real-time data collection from over 300 monitoring points. As a result, fault prediction accuracy reaches an impressive 98%, significantly reducing annual downtime to less than 2 hours.

2. Guangzhou Metro: A Model for Space Optimization and Energy Efficiency Enhancement

Guangzhou Metro's new line features Blokset switchgear deployed at substations and along-route distribution rooms, achieving a 30% reduction in equipment footprint thanks to its compact layout. Inside the cabinets, low-resistance copper busbars (with contact resistance ≤30μΩ) and active filters are used, cutting system energy consumption by 15% and resulting in annual electricity cost savings exceeding 2 million yuan. The modular design allows for on-demand expansion—for instance, an initial configuration of 12 functional units at a key transfer station can later accommodate increased power demands from a newly developed commercial area simply by adding more drawers, thus eliminating the need for a full-scale renovation.

3. Shenzhen Metro: Precision Energy Management in Commercial Areas

Shenzhen Metro has implemented Blokset switchgear in commercial areas of select stations to enable individual household metering. Each shop’s distribution drawer is equipped with an intelligent electricity meter and a remote control module. The operation and maintenance platform can monitor the electricity consumption patterns of over 200 tenants in real time, automatically generating energy efficiency analysis reports. Data from 2024 show that by dynamically adjusting lighting and air conditioning strategies, the commercial area achieved an 18% reduction in energy consumption per unit area, while disputes over electricity bills were cut by 70%.

II. High-Speed Rail System: Key Support Ranging from Traction Power Supply to Emergency Assurance

Beijing-Shanghai High-Speed Railway: The Cornerstone of Stable Catenary Power Supply

At a traction substation along the Beijing-Shanghai High-Speed Railway, GCK-type withdrawable switchgear undertakes the 35kV-to-10kV step-down task. The cabinet is equipped with an automatic dual-power switching device, which ensures seamless power supply to the catenary system by automatically engaging the backup power source within 0.3 seconds in case of a primary line failure. The drawer units feature a "five-protection" interlocking design—preventing incorrect disconnection or connection, blocking energized closing operations, preventing grounding while energized, guarding against unauthorized entry into live compartments, and avoiding load break operations under load—resulting in zero operational errors recorded throughout 2024.

2. Xi'an East Station: Innovative Practices in the Relocation and Renovation Project

In 2025, during the construction of the elevated expressway at Xi'an East Station, the Municipal East Company deployed 10 12-megawatt generator vehicles using汇流柜 (busbar distribution cabinet) technology for efficient power allocation. Traditionally, distributed access would require setting up 8 separate connection points; however, the匯流櫃integrates these loads onto a centralized busbar system, reducing the number of access points to just 3. Inside the cabinet, an advanced intelligent load-monitoring system is installed, enabling real-time adjustments to the output power of each generator vehicle—thus preventing risks like overloading and disconnection. Throughout the relocation and renovation process, continuous power supply was maintained at 12,000 kilowatt-hours, ensuring zero power outages for 9,875 households.

3. Harbin-Dalian High-Speed Railway: Reliability Verification in Extreme Cold Conditions

On a certain section of the Harbin-Dalian High-Speed Railway, enhanced withdrawable switchgear has been deployed under extremely cold conditions as low as -35°C. The cabinet features a double-layer steel plate structure with a polyurethane insulation layer filling the space in between, while an internal heating module automatically maintains an operating temperature above 0°C. Additionally, the drawer-unit contactors are equipped with silver-cadmium oxide contacts, boosting arc erosion resistance by up to three times—resulting in a 65% reduction in failure rates during winter 2024 compared to conventional equipment.

3. Technological Breakthrough: The Evolutionary Path from Isolation Design to Intelligent Solutions

1. A Triple Isolation System Ensures Safety

Modern withdrawable switchgear features triple protection: longitudinal (metal-plate isolation of busbars/cables), transverse (physical partitions between drawers), and grounding (equipotential bonding across the entire cabinet). For instance, Blokset switchgear is certified to IEC 61439-2, withstanding short-circuit currents up to 100 kA/1s, and achieving an IP43 protection rating—making it resistant to harsh conditions such as humidity and salt spray.

2. Intelligent upgrades enhance operational efficiency

The fourth-generation product, integrating IoT technology, now enables functions such as condition monitoring and predictive maintenance. The intelligent cabinet units deployed on Shanghai Metro Line 14 utilize edge computing nodes to analyze parameters like vibration and temperature, providing a 30-day early warning of contactor aging. As a result, the replacement cycle for spare parts has been extended from 2 years to 5 years, reducing lifecycle costs by 40%.

3. Standardized modules facilitate rapid deployment

The MNS, GCS, and other series of cabinets adopt the IEC 60297 standard dimensions, with drawer unit heights based on a 200mm module, allowing for flexible combinations of functional units. Guangzhou Metro Line 18 completed the installation and commissioning of all 68 cabinet panels along the entire line within 30 days—achieving three times greater efficiency compared to conventional fixed cabinets.

IV. Future Trends: Green Energy Efficiency and Full Lifecycle Management

As the "Dual Carbon" goals advance, the rail transit sector is placing higher demands on withdrawable switchgear. Schneider Electric’s EcoStruxure architecture leverages digital twin technology to simulate the operational status of switchgear cabinets, optimizing energy consumption by 5%–10%. Meanwhile, the use of recyclable materials has increased from 30% to 75%, reducing the carbon footprint of each cabinet by 2.3 tons over its lifecycle.

Moreover, as artificial intelligence and big data technologies become increasingly integrated, the智能化 level of withdrawable switchgear will enter a brand-new phase. Machine learning–based fault diagnosis systems can leverage vast amounts of operational data to build dynamic models, enabling precise identification of early, subtle faults—and reducing maintenance response times from hours to minutes. On the operations and maintenance management front, the application of blockchain technology ensures tamper-proof traceability of equipment’s entire lifecycle data, creating reliable digital records for every stage, from raw material procurement to end-of-life recycling. This, in turn, provides an accurate foundation for carbon footprint calculations. Meanwhile, in response to extreme climates and challenging geographic conditions, new composite-material cabinet designs are currently under development. These cabinets boast corrosion resistance that is five times better than traditional metal materials, while also being 40% lighter in weight. As a result, they can significantly cut down transportation and installation costs in specialized environments such as plateaus or coastal regions. Notably, with the widespread adoption of private 5G networks, switchgear is set to evolve into edge computing nodes within the energy internet infrastructure of rail transit systems. This transformation will enable real-time coordination with train control systems and environmental monitoring devices, allowing for dynamic optimization of power supply strategies. Looking ahead, withdrawable switchgear of the future will no longer be confined to mere power distribution functions—it will emerge as an integrated energy hub for rail transit, combining safety protection, intelligent decision-making, and eco-friendly, low-carbon features. Such advancements will continue driving the industry toward greater efficiency and sustainability.

Key words:

MNS switchgear: Providing stable power for heavy industries such as petrochemicals and metallurgy.

High-voltage switchgear ensures stable operation of power plants in grid transformation applications.

Hunan Chengyuan Electrical CO.,LTD

Case Study on the Application of Withdrawable Switchgear in Subways and High-Speed Railways

2. Xi'an East Station: Innovative Practices in the Relocation and Renovation Project