East Japan Railway Company
Effectively utilizes energy from regenerative power from running trains ……
[Table 2: https://prtimes.jp/data/corp/17557/table/845_1_76b52ec682d4e39ff88c14963c402223.jpg] *1 Feeding voltage: The voltage of electricity used by trains to run. *2 Regenerative power: Electric power generated due to brake operation *3 Part of the Yokosuka Line section: Approximately 10km between Nishi-Oi and Shin-Kawasaki
1. Effective use of regenerated power by reducing feeding voltage (sending) (1) Mechanism of regenerative power
The train accelerates with the power supplied from the overhead wires, but when decelerating, the train’s kinetic energy is converted into electrical energy to generate regenerative power. Energy consumption on railways is reduced by supplying the generated regenerative power to trains running nearby for effective use.
[Image 1: https://prtimes.jp/i/17557/845/resize/d17557-845-a19e3ea4e6b0c45066ef-0.png&s3=17557-845-5d910f6d76e973e5c257507643ea373d-934×472.png ]
Figure 1 Generation and use of regenerative power
(2) Initiatives for effective use of regenerated power
When there is no power running vehicle*4 in the vicinity of the regenerative vehicle, when the feeding voltage increases due to the generation of regenerative power and reaches a certain voltage, the regenerative power is suppressed (regeneration throttling) to prevent equipment failure. Therefore, the energy that can be used by other trains cannot be used effectively. Therefore, we have been
investigating ways to make more effective use of regenerative power by reducing the standard feeding voltage supplied from substations to create a situation in which regenerative throttling is less likely to occur.
On the other hand, if the feeding voltage is reduced, the acceleration performance of trains running in the relevant section will decrease, and there is a concern that it will affect the train operation schedule, but it is necessary to understand the sections where regenerative power is likely to be suppressed using vehicle data etc. This makes it possible to suppress the feeding voltage without affecting train operation schedules.
*4 Power running vehicle: A train transmits motor power to the axle to accelerate or maintain speed on an uphill slope.
[Image 2: https://prtimes.jp/i/17557/845/resize/d17557-845-62b37662dea389530578-1.png&s3=17557-845-7e1f5cc418b210a5b31802bea3980b1f-1057×602.png] Figure 2 Effective use of regenerated power by reducing feeding voltage (3) Line sections to be introduced
We will conduct a demonstration experiment on the effective use of regenerated power by reducing feeding voltage at Yokohama Line Kozukue Station to Hachioji Station, where the number of trains is relatively small and the amount of electricity used is small, and full-scale operation will begin in June 2023. I am. In addition, the Saikyo Line, which has a similar number of train sets to the Yokohama Line, has begun a similar demonstration experiment in October 2023, and the Nambu Line will also begin a demonstration experiment in June 2024. From May 2024, we will begin long-term demonstration experiments between Nishi-Oi Station and Shin-Kawasaki Station on the Yokosuka Line, which have a large number of trains and consume a large amount of electricity. We hope to reduce energy consumption by approximately 3% (CO2 equivalent: approximately 300 tons/year) in this section, and will consider transitioning to full-scale operation based on the results of the demonstration experiment.
[Image 3: https://prtimes.jp/i/17557/845/resize/d17557-845-0270485a5f338c84e4fc-2.png&s3=17557-845-e8d0ae4c60f0a33d9a59e14431e414d3-1126×472.png ]
Figure 3: Section of effective use of regenerated power by reducing feeding voltage
2. Promoting the introduction (storage) of equipment for effectively utilizing regenerated power
In addition to effective use of regenerative power by reducing feeding voltage, we are also using energy storage devices to temporarily charge and supply accelerating trains when there are no powering vehicles in the vicinity of regenerative vehicles, and regenerative inverters to supply stations, etc. We are also proceeding with the introduction of equipment. So far, we have installed four power storage devices and three regenerative inverters.
[Image 4: https://prtimes.jp/i/17557/845/resize/d17557-845-3a3d18b9af1c46ce57b6-3.png&s3=17557-845-2162e2af8052a749c1e86407405942a3-1280×470.png ]
[Image 5: https://prtimes.jp/i/17557/845/resize/d17557-845-49c3d218f52d87dfb251-4.png&s3=17557-845-450a281515959e450fde040ff0038258-1280×466.png ]
Figure 4 Introduction of equipment for effective use of regenerative power 3. Effective use of future “send” phase
In the future, we will consider expanding the effective use of regenerated power by reducing feeding voltage, focusing on railway lines in the metropolitan area. Additionally, the number of trains running varies greatly between rush hours and other times. Therefore, it is expected that adjusting the feeding voltage depending on the time of day will lead to even more effective use of regenerated power. Contribute to the Zero Carbon Challenge and reduce energy costs by considering the introduction of substation equipment that can automatically adjust power voltage according to loads such as the number of trains running, and by analyzing various data obtained from rolling stock and substations. I will connect it to.
[Reference] Energy Vision 2027
In July 2022, we formulated “Energy Vision 2027 ~Connecting~” as the energy strategy that the JR East Group is aiming for. We are promoting initiatives to improve (environmental efficiency, economic efficiency, stability) and lead to the sustainable development of C (local community). We aim to reduce CO2 emissions for the entire JR East Group to “virtually zero” by fiscal 2050. (URL:
https://www.jreast.co.jp/eco/pdf/energy_vision2027.pdf)
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