Technology company ABB 1500 Volt DC Enviline Roadside Energy Storage System (ESS), a three-year project, captures braking energy and then returns it to accelerate other trains that later use the same section of line.
The energy is regenerated into electricity for use in other trains, but can also be sent back to the grid through this storage system. Previously, this excess wasted intro resistors, as only part of the energy can be taken at once.
Metro Trains Melbourne required an ESS solution for high-capacity, high-voltage environments. ABB has previously developed ESS solutions for 750-volt railways in the United States and Europe. However, in the southern states of Australia, railways require 1,500 volts.
Antonio Cola, Global Rail Marketing and Sales Manager at ABB, says: “ABB’s ESS is also used to manage voltage drops. By their nature, trains experience power peaks during acceleration, which can cause a drop in voltage and lead to performance problems, causing costly delays.
“This can also lead to high search fees and peak sanctions from the utility company, especially during peak hours. As it returns energy during acceleration, ESS limits the power extracted from the grid and maintains the voltage level along the line.
“This reduces the associated utility charges and can be used in some cases as an alternative to avoiding or postponing potential capital investments for new traction substations and additional contracts with utility companies.
The system stabilizes the demand for network power and provides energy cost-benefit. Regenerative braking systems provide an opportunity to improve the energy efficiency of traction systems due to the regular braking that is performed every day, with a recoverable excess braking energy of up to 30%.
This sustainable technology also reduces dust and air pollution that are released during traditional braking. The frequency of mechanical braking is reduced during descent, which reduces the maintenance and replacement of the train’s brake pads, reducing the wear of a conventional mechanical braking system.
This solution has the potential for critical backup power in the event of a power outage or utility instability, as operators can access stored train power to a place where passengers can get off the train.
With regard to safety, Cola says: “As part of a greater focus on safety, the Melbourne Metro team subsequently called for further safety improvements in the design to include an automatic earthing switch so that equipment can be grounded just by pressing switch. ”
Through this solution, Metro aimed to guarantee customers a smoother journey and increase the frequency of trains on the line. This energy management system is cost-effective in terms of land use and construction, and also reduces carbon emissions by 15%.
Kola adds: “Although regenerative braking systems are not a new technology, they have only recently come to the fore as a vital eco-innovation for the urban transport industry.
“As projects like Melbourne Metro continue to demonstrate the enormous environmental, cost and operational benefits of this technology, we will see more other railway operators looking for some sustainable energy recycling action.