ENVILINE ERS is a wayside Energy Recuperation System that saves the surplus braking energy of a train by returning it back to the AC network, thus reducing the total energy consumption of DC rail transportation by 10 – 30 percent. The ERS is part of the ENVILINE energy management portfolio that also includes Energy Storage System (ESS) and Energy Dissipation System (EDS). ABB presented the ENVILINE energy management solutions at the UITP world exhibition 2013 in Geneva.
When decelerating or braking, a traction vehicle (train, tram or trolleybus) is feeding the regenerated braking energy back into the DC power network. Typically, if braking energy is not used by other vehicles in the network, it must be dissipated by the onboard braking resistors. To meet the demands on energy recuperation in traction infrastructure, ABB introduces ENVILINE Energy Recuperation System (ERS). Instead of dissipating, the ERS saves the surplus braking energy of the train by returning it back to the AC grid. It is a modular, IGBT based inverter system installed at the DC substation and connected in parallel with the existing diode rectifiers that can be scaled according to the customer’s needs. In addition, the ERS can improve the quality of the AC power network through harmonics and reactive power mitigation, and due to bidirectional operation it can offer support to the existing rectifiers through active rectification.
If connection to the AC grid is not available, ENVILINE ESS (Energy Storage System) is the right solution for high energy efficiency. The ESS stores the surplus braking energy and feeds it to the power line to assist the acceleration of the train. The ESS can come with either super capacitors for short storage and recovery or with batteries for longer storage. The system improves traction power quality and manages peak power demand; it can also be used as a standalone traction power system, permanently installed or mobile, to replace conventional grid-connected traction power systems. When used with batteries, ESS can also provide emergency power and generate revenues by participating in the local energy markets.
Energy Dissipation Device (EDS) completes the ENVILINE energy management suite of solutions. The EDS ensures track receptivity during the regenerative braking by dissipating all surplus energy that cannot be absorbed by other onboard loads / nearby trains, nor recovered by the ERS or ESS. By deploying the wayside EDS instead of onboard resistors, the rail operator reduces the train’s weight and energy consumption, and also eliminates accumulation of heat caused by braking in tunnels and underground stations.
ENVILINE energy management solutions are already in successful operation around the world. The public transportation system in and around Philadelphia city (USA) and the Warsaw metro (Poland) are among our latest references.
With ENVILINE family of products, ABB is offering the right solution for each DC network environment. The family also includes traditional power supply components such as transformer and rectifier, necessary to power traction vehicles; and protection devices, for example automatic grounding system and platform bonding device.