The E³ Solution System is an energy storage system that effectively stores and supplies energy that might be wasted, enabling railway operators to reuse and conserve energy.
Overview
The E³ Solution System was jointly developed by Toyo Denki and GS Yuasa International Ltd. as a railway energy storage system. The main components of the system are new high capacity lithium-ion batteries and a bidirectional DC/DC converter.
The three main advantages of the system are compensation for voltage drops, storage of regenerative energy and peak-cut of power demand. Adopting the E³ system as an auxiliary system for substations enables railway operators to save energy and to prevent global warming.
Installation for Kagoshima City Transportation Bureau
E³ stands for "Energy, Ecology and Economy," the three major benefits of the system for railway operators.
Benefits
Reuses effectively energy and significantly reduces costs as an alternative to building new substation.
Energy Conservation
Energy
Less power consumption
Gentle on the earth
Ecology
Does not dissipate regenerative energy as heat
Converter enables control of rapid energy storage and discharge (Without bullet)
Batteries with high efficiency (Without bullet)
Cost reduction
Economy
Reduces the need for new substations and the resulting cost of construction
Minimizes the need to increase electricity contracts
Minimizes the need to increase equipment capacity for receiving electricity
Features
Compensation for voltage drops
Voltage drops proportionally to resistance (distance from substation) and to current (flowing through the overhead line). These voltage drops are accentuated during peak hours of railway operation when many trains are in service. The E³ Solution System uses lithium-ion batteries to store electrical energy, in order to compensate for voltage drops of the overhead line.
Storage of regenerative energy
Trains equipped with a regenerative braking system are designed to return electrical energy to the contact line when braking to decelerate or stop. The E³ Solution System stores regenerative energy unavailable to other trains, and effectively discharges the stored energy as required.
Before: Behavior of overhead line voltage
After Installing E³ Solution System: Behavior of overhead line voltage
Peak-cut of power demand
Peak power demand during rush hours can lead to higher electricity cost. The E³ Solution System can provide stored energy to trains as instant energy in place of energy from a substation. Consequently, peak power demand can be cut down.
System Diagram
System Capacity
Overhead line voltage
System capacity
600V
750V
180kW
360kW
540kW
1,500V
360kW
720kW
1,080kW
Notes:
1. Please contact us for detailed system dimensions and weights.
2. System capacity is rated at 30 seconds.
Examples of Installed Systems
West Japan Railway Company
Installed location
Shin-hikida Substation, Hokuriku Main Line
First installed
September 2006
System capacity
1080kW
Issues addressed
Compensation for voltage drops
Storage of regenerative energy
Description
The customer installed the E³ Solution System to compensate for voltage drops due to transformer substation outages, caused by the limitation of one power receiving line from the power utility. The installed system operates to continually absorb and store regenerative energy.
Kagoshima City Transportation Bureau
Installed location
Sakurajima Sanbashi-dori and Nakasu-dori stations
First installed
April 2007
System capacity
250kW
Issues addressed
Compensation for voltage drops
Storage of regenerative energy
Description
The customer installed the E³ Solution System to address chronic voltage drops from overhead lines and resulting trolley stoppages at two locations that are at a distance from transformer substations.
[Inquiries about product information and sales]
Transportation Business Division
Tel: +81-3-3535-0641
(C) 2010
TOYO DENKI SEIZO K.K. All Rights Reserved
