Rail Transit And Photovoltaic Power Station Scenarios Expand, Broadening The Application Boundaries Of Vacuum Circuit Breakers - News

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Expand into emerging scenarios

With advantages such as strong arc-extinguishing capability, low maintenance, and no risk of gas leakage, vacuum circuit breakers are rapidly expanding from traditional distribution networks to emerging scenarios such as rail transit and photovoltaic (PV) power stations.

In the field of rail transit

In the field of rail transit, DC power supply systems are typically used for the traction power supply systems of subways and city rail systems.DC arcs have no natural current zero crossing, making them much harder to extinguish than AC arcs. DC vacuum circuit breakers based on the forced commutation principle, which use commutation capacitors in coordination with vacuum switches to create current zero crossings, have become an important solution for protection in DC traction power supply systems. By the end of 2024, more than 50 cities in mainland China had opened urban rail transit, with operating mileage exceeding 12,000 km, and the demand for DC vacuum circuit breakers has continued to grow accordingly. At the same time, rail transit imposes high requirements on equipment size, seismic resistance, and maintenance-free performance, driving vacuum circuit breakers toward compactness and higher reliability.

In the field of PV power stations

In the field of PV power stations, both centralized and distributed projects require large numbers of circuit breakers for grid connection and fault isolation. The DC side voltage of PV systems can reach 1,500 V, and DC fault arcs are difficult to extinguish naturally and can easily cause fires. DC vacuum circuit breakers, combined with fast detection technology, can effectively interrupt fault current. In addition, PV power stations are often built in northwest deserts, coastal mudflats, or coal mining subsidence areas, where wind-blown sand, salt spray, and large temperature differences impose higher requirements on equipment anti-corrosion, dust prevention, and wide-temperature adaptability. Domestic manufacturers have optimized insulation design, sealing structures, and surface treatment processes for these scenarios, improving environmental tolerance.

Extension of the Application Boundary

From DC traction to PV grid connection, the application boundaries of vacuum circuit breakers are extending from AC distribution networks to DC systems, and from conventional environments to harsh operating conditions. This trend reflects both the demand pull from renewable energy and rail transit construction and the continued progress of vacuum interruption technology toward DC-oriented, compact, and highly environmentally adaptable development.