How to choose the suitable power supply method for electric rail?

As an enterprise deeply engaged in the R&D and landing of electric rail, we know that the power supply method is the “heart” of the stable operation of electric rail. In the past five years, we have participated in the design of power supply scheme of 23 electric rail projects, from city subway to scenic spot sightseeing electric rail, and summarized the core logic of choosing power supply method for electric rail in practice.

The first thing to do is to choose the suitable power supply method for electric rail, which should closely follow the characteristics of the scene. In the electric rail project in the core area of the city, contact network power supply is a common program. For example, in a provincial capital metro electric rail project, the line passes through the business district, the contact network cooperates with the pantograph through overhead line, adapts to the demand of 80km/h high-speed operation, has a large power supply capacity and adopts rigid suspension in the tunnel to reduce the headroom occupation. In the area of dense ancient buildings, we optimize the pillar design and use light contact network to balance the stability of power supply and landscape protection.

The electric rail of closed scene is more suitable for the third rail power supply. An industrial park transit electric rail speed of 30km/h or less, the third rail through the electrified rail and collector boots contact, eliminating the overhead structure, reducing construction costs, but also to avoid the risk of collision of plant machinery on the line. We add insulation shield and intelligent monitoring system to ensure the safe operation of electric rail in industrial environment.

The value of energy storage power supply is highlighted in special scenes. A mountain scenic spot sightseeing electric rail through the mountains and forests, the contact network or the third rail will damage the ecology, so it adopts the energy storage type power supply: the vehicle in the station fast charging to replenish the energy, the midway by the battery operation, the whole process of no overhead line, suitable for scenic spots, “Zero Pollution” requirements. We with lithium iron phosphate battery, 10 minutes fast-charging range of 50 kilometers, meet the needs of 12 hours of operation.

Technical suitability and economy are equally critical. City fast rail electric rail speed over 100km/h, relying on contact network high-current power supply; community slow rail speed 20km/h, the third rail low-loss characteristics are better. In terms of cost, the contact network construction cost is high but long life, the third rail saves money at the initial stage but maintenance is frequent, the energy storage battery needs to be replaced regularly but the scene adaptability is strong.

There is no “best” power supply method, only the “most suitable” electric rail program. In the future, we will explore the hybrid power supply mode, so that the electric rail can realize “safe, efficient and green” operation in more scenarios, which is exactly the original intention of our deep cultivation.