Hitoshi Hayashiya

Cost impacts of high efficiency power supply technologies in railway power supply - Traction and Station -

Railway transportation is one of the most eco-friendly transportation way. The amount of energy consumption, however, for railway transportation is not so small that it is important to make effort to enhance eco-friendliness of railway transportation continuously to realize low carbon society in the future. In this paper, the tested and calculated impact of high efficiency power supply and energy saving technologies in railway power supply system for traction and station, office etc. are compared. As an advanced technology, not only the impact of energy storage devices for regenerative energy utilization but also that of smart grid technology in railway power supply system is mentioned. Such a comparative study will be instructive to draft a cost target for future development of smart grid and renewable energy technology.

Potentials, peculiarities and prospects of solar power generation on the railway premises

In this paper, the potentials, peculiarities and prospects of solar power generation system to the platform roofs of the railway station will be discussed. Based on the rough estimation, the total potential of our company for platform roof PV system is amount to be more than 100MW. While the railway premises have such a high potential for solar power introduction, they have also difficulties compared to the other mega-solar systems utilizing the vast extent of land and utility power grid. As future prospects, the realization of solar generation system with lithium ion batteries for local station called “zero-emission station” will be also shown in this paper.

Survey of power electronics and electric machine application for on-site railway power system in Japan to realize eco-friendly transportation

In this paper, a survey of novel applications of power electronics and electric machine technology for on-site railway power supply system during the last decade in Japan to realize environmentally friendly transportation is conducted. The applications for high speed railway transportation called Shinkansen are described in Chapter 2 and for conventional railway are in Chapter 3. Not only the technologies which have been put into practical use but also the technologies which are just proposed and tested are introduced. The railway transportation in Japan has already realized CO2 emission index about 19g-CO2/person-km while the index of car is about 168g-CO2/person-km. Electrification is, as a matter of course, key technology to realize such a eco-friendly transportation and its system progresses day by day applying power electronics and electrical machine technologies. The continuing effort of railway companies and manufacturers in Japan to make the system more reliable and more ecological will be grasped in this paper.

Effect evaluation of Li-ion battery for regenerative energy utilization in traction power supply system

Two Lithium ion battery systems have already installed at practical traction substations, HAIJIMA SS and OKEGAWA SS, to utilize regenerative energy in d.c. 1.5kV traction power supply system of East Japan Railway Company. In this paper, the effect of energy storage system for energy saving by making use of regenerative energy is evaluated in detail. According to our experiences, the annual effects of energy storage systems at HAIJIMA SS and OKEGAWA SS are 400MWh/year and 600 or 700MWh/year, respectively.

Lithium-ion battery installation in traction power supply system for regenerative energy utilization Initial report of effect evaluation after half a year operation

Previously, some energy storage systems were installed to compensate for voltage drop and to avoid regenerative brake cancelation in d.c. 750V and 1.5kV traction power supply system in Japan. The fly wheel and Lithium-ion (Li-ion) battery, nickel metal hydride (Ni-MH) battery and electric double layer capacitor (EDLC) were used as a storage device. In East Japan Railway Company, Li-ion battery system was installed at HAIJIMA Substation (SS) on Ome Line and started operation on February 20th, 2013. It is the first application of the energy storage system mainly not for voltage drop compensation but for regenerative energy utilization. In this paper, the effect of Li-ion battery system installed at HAIJIMA SS is evaluated based on the measured data during the practical operation and it is shown that it contributes to more than 5% reduction of total traction power supply at HAIJIMA Substation. The future plan of energy storage application is also mentioned.

Possibility of energy saving by introducing energy conversion and energy storage technologies in traction power supply system

After the 3.11 earthquake in Tohoku district in Japan, energy saving and renewable energy utilization become one of the important problems in Japan. East Japan Railway Company, as a public transportation company, tries to contribute to solve these problems by realizing eco-friendly railway transportation system. In this paper, three realized and under construction projects are summarized which enhance efficiency of traction power supply system. First project is installation of lithium ion battery at Haijima Substation on February 20th, 2013 to make use of regenerative power in d.c. traction power supply. Second project is the power conversion application to be installed at Ushiku sectioning post for a.c. traction power supply and will start operation in the end of 2013 fiscal year. The last project but not least one is “zero-emission station” realized at Hiraizumi Station on June 28th, 2013. The total electric power of the station is supplied from solar power even in the evening using lithium ion batteries. The detail of the operation data of “zero emission station” is shown in this paper.

A study on a preventive system of wire break triggered by direct lightning strokes on to DC railway feeding systems

The wires of DC electric railway feeding circuit may be broken by a direct lightning stroke. This kind of trouble occurs not so frequently; however, once it occurs, it makes a great disturbance of train operation. We assumed the process of wire break, and we are now studying a new preventive system of wire break caused by ground faults triggered by lightning strokes. The result of basic test shows the possibility of detecting such ground faults before the break of the wire; however, there remain some problems which should be solved before practical system construction.

Proposal of lightning risk assessment method based on the lightning current probability function for railway power supply system

A novel assessment method of breakdown probability at suspension insulators supposing the railway DC power supply system are proposed in this paper. This method is based on the well known lightning current probability function and comparison of lightning endurance of traction wire system between conventional DC railway and Shinkansen is performed. It proves that the introduction of grounding wire in DC railway power system is able to avoid only 36% of flashover at supporting point. The experimental data to confirm the influence of long tail lightning current on tensioned wire and insulators are also shown.

Application examples of energy saving measures in Japanese DC feeding system

In this paper, some application examples of energy saving measures in two representative Japanese railway companies, mainly in d.c. electric traction power supply system, are introduced. The effect of electric energy storage systems installed to substations is mentioned especially. In addition, it is also described about the potential of regenerative braking energy, which will be able to be utilized by installation of energy storage systems or other measures.

Investigation and enforcement of comprehensive lightning protection in Tokyo metropolitan area railway system

In this paper, our policies for lightning protection in electronic and electrical equipments for railway transportation in Tokyo metropolitan area are summarized. Conventionally, we tried to improve lightning protection characteristics in each section such as signaling, communication and power supply section independently. Reflecting the equipments damage in summer of 2008, we reconsidered our countermeasures. Not only the proposed and enforced countermeasures in each section but also comprehensive countermeasures such as total grounding system design will be shown.