The Melbourne tram network is the largest in the world, consisting of 250 km of double track that is serviced using a range of trams and modern light rail vehicles (LRVs) of varying age and configuration.
Over recent years, the proportion of modern LRV’s in the fleet has increased, as longer low-floor trams with greater carrying capacity and air conditioning systems are introduced to replace older rolling stock.
These modern LRV’s place increasing demand for energy on the network’s traction power system, particularly in congested areas such as Melbourne’s CBD.
As a result, converter stations are stretched, which can result in voltage drops in the overhead wiring system in these sections of the network. This problem will be exacerbated as more of the older rolling stock is retired from service and replaced by modern high capacity vehicles.
Bombardier has been working with the State of Victoria to help address these network and operational challenges in the form of an Energy Saver device that could be retrofitted to existing E-Class trams, or other tram fleets, in order to reduce strain on the network.
Bombardier has developed its MITRAC Energy Storage technology for the Mannheim light rail network in Germany. This system has been in operation since 2010 and installed on various fleets to improve the stability of the power network.
The Energy Saver system, as installed on the Mannheim trams, has provided the following benefits:
• Up to 30% Energy saving
• Up to 50% lower Peak Power drawn from Network
• Up to 50% lower voltage drop
The Energy Saver is designed to be integrated with the traction converter equipment and is a super capacitor that absorbs energy during the braking process and stores it.
During the acceleration phase, and whilst driving, this energy is released to the traction system, reducing the energy consumption from the contact wire.
Over the entire power train, savings of between 23 percent up to a maximum of 30 percent of the energy consumed via the contact wire can be saved, however this is highly dependent on the operational constraints.
You can hear more about the technology Bombardier is developing to address the specific needs of various Australian transport networks at Informa’s Light Rail 2019 Conference – due to take place 4-5 March at the Crown Plaza, Melbourne.