Application of super capacitors in trams

With the acceleration of the country’s urbanization process, the urban population of various localities is gradually increasing. The flow of population and the increase of road vehicles have further aggravated the congestion of urban traffic and environmental pollution. Modern tram is a medium-to-low-volume urban public transportation. It has the characteristics of short construction period, lower overall construction and operating costs than subways, and no independent rights of way. It is favored by large, medium and small cities.

Among them, energy-storage trams effectively solve the traditional way that the tram system needs to set up catenary power supply along the way, and it has been widely used.

The most common type of energy storage power supply equipment is super capacitors, but with the continuous development of new energy technology, hydrogen fuel cells have gradually entered the field of rail transit. In particular, the opening and operation of Gaoming Hydrogen Energy Tram has provided a new sample of energy storage equipment.

Hydrogen energy is a kind of secondary energy, which is quite different from super capacitors. Its technical principles, system structure and operation performance in trams have different characteristics. Compare and analyze these two types of typical energy storage. The performance of this type of equipment in the application of trams provides a reference for the application and improvement of hydrogen energy in trams.

Supercapacitors, also known as electric double layer capacitors, are a new type of energy storage device based on new materials and new processes developed in the 1960s. They use an electric double layer composed of activated carbon porous electrodes and electrolytes. The structure obtains a large capacity and stores energy through the separation of charges on the surface of the electrode, and the Faraday reaction does not occur on the electrode. It not only has the characteristics of fast charging and discharging of capacitors, but also has the energy storage characteristics of batteries, and can provide higher energy density than physical capacitors, higher power density and longer cycle life than batteries.

Based on the frequent start-up of trams and the large amount of current, supercapacitors, as an independent on-board energy storage device, can better meet the running needs of trams. At present, trams that use super capacitors as energy storage devices for independent power supply have been widely used on multiple lines in Guangzhou, Shenzhen, Wuhan, and Huai'an.

The energy storage type modern trams that use super capacitors as energy storage components, and the power supply system structure is mainly composed of roof receiver systems, super capacitor systems, etc. Among them, the roof power receiver generally adopts a single-arm light-duty power receiver. When the vehicle is running, the power receiver is always in a raised state. When the vehicle enters the station area, the power receiver contacts the power supply rail and collects current from the power supply rail. , Use the short train stop time to quickly supplement the electric energy for the super capacitor.