Railway Substations Research Articles

Analysis Method and Abatement Measure of Magnetic Fields Emitted from Electrified Railway Substations

Recently, electromagnetic environments and electromagnetic compatibility (EMC) in relation to electrical equipment have become important issues. In 2008, the European Union established the EN 50500 standard, which provides measurement and calculation methods for determining magnetic fields emitted from electrical equipment on railways. The major frequency components of the electric and magnetic fields generated from such equipment are in the low range, such as D.C., 16.7 Hz, 50 Hz, 60 Hz and their low-order harmonics. According to the EN 50500 standard, magnetic fields are dominant around this kind of equipment. This paper describes the physical characteristics and analytical methods of low-frequency magnetic fields emitted from electrical equipment in railway substations, and proposes abatement measures and model substation designs based on the above results.

高速鉄道変電所電力変動のファジィ平滑化制御

The use of an SMES (Superconducting Magnetic Energy Storage) for smoothing power fluctuations in a railway substation has been discussed. This paper proposes a smoothing control method based on fuzzy reasoning for reducing the SMES capacity at substations along high-speed railways. The proposed smoothing control method comprises three countermeasures for reduction of the SMES capacity. The first countermeasure involves modification of rule 1 for smoothing out the fluctuating electric power to its average value. The other countermeasures involve the modification of the central value of the stored energy control in the SMES and revision of the membership function in rule 2 for reduction of the SMES capacity. The SMES capacity in the proposed smoothing control method is reduced by 49.5% when compared to that in the nonrevised control method. It is confirmed by computer simulations that the proposed control method is suitable for smoothing out power fluctuations in substations along high-speed railways and for reducing the SMES capacity.

Control system for the switched reluctance drive of a flywheel energy‐storage module

AbstractThis paper presents a novel control system for the operation of a flywheel energy‐storage (FES) module used for power peak shaving in high‐speed railway substations. A double power converter drives a switched reluctance machine (SRM) along with a flywheel operating in a wide speed range. An innovative controller architecture based on modular microcontrolled boards connected through a CAN network is introduced. Standard switching patterns are modified to reduce iron and semiconductor losses and to improve harmonic performance. Experimental results for a 140 kW/5 MJ prototype are presented confirming controller compliance with the system specifications and requirements. Copyright © 2007 John Wiley & Sons, Ltd.

전기철도 차량기지 변전소의 실시간 무효전력/역률 보상설비 적용에 따른 전력품질 개선에 관한 연구

In this paper, real-time reactive power/power factor compensating equipment is suggested for improving power quality at electrical railway's substation in marshalling yard and designing optimal capacity of compensating equipment for actual apply at current marshalling yard. For this purpose, several kind of real-time reactive power/power factor compensating equipments are introduced and SVG(Static Var Generator) as optimal compensating equipment that is suitable for load characteristics of substation in marshalling yard is suggested. This paper shows proper simulations by suggested equipment using PSIM software and describe basic compensating principle and simulation results. Optimal capacity design for applying current marshalling yard is based on real measured power quality data. Power quality improvement that is performed by SVG as real-time reactive power/power factor compensating equipment is estimated at electrical railway's substation in marshalling yard. As reference, real-time reactive power/power factor compensating equipment is composed by voltage source inverter and DC capacitors.

A Hybrid Energy Storage With a SMES and Secondary Battery

An energy storage device with high energy density and high power density is desired for compensation of fluctuating loads such as railway substations and distributed generations such as wind turbines. Typically, a SMES (Superconducting Magnetic Energy Storage) has higher power density than other devices of the same purpose, and secondary batteries have higher energy density than SMES. In this study, the authors propose a hybrid energy storage system composed of a superconducting magnet and secondary battery for an energy storage system with high energy density and high power density. The sharing method of power for each storage device using a Fuzzy control and filters, simulation for the compensation of railway loads and the power of wind turbines are presented.

Innovations in the Automation of the Electric Power Railway Substations

This paper highlights the main problems connected to the technological renovation of infrastructures applied for electrical supply of the contact line. This paper has been developed in cooperation with RFI (the Italian Railway Network), addressing with particular attention the railway electrical substations (ESS). The purpose of this study consists of the identification of some innovative technical solutions for the realization of3kV(sub dc)ESS. In fact, to satisfy the increase of market demand for railway transport during the next 10 years, the whole Italian electrical railway network has to be radically improved. The paper briefly analyze the actual status of the RFI ESS structures, and point out the limitations of the traditional technologies. From this study, it is evident that there is a need to critically analyze two crucial aspects of the modernization: some strategies of interventions are proposed, with the purpose of achieving a convenient technical-economic management for the infrastructure.

Development of a DC Feeding Bus Ground Fault Detection System for Railway Substations

This paper describes a new system for detecting bus ground faults at DC railroad substations. High voltage DC ground relays are in place to detect DC feeding circuit ground faults at substations. Train operations can be severely disrupted if such ground faults occur. The proposed method is designed to detect DC bus ground faults at a substation in question without the influence of unrelated faults. The system involves the of discharging gaps and return wire fault selective relays as a way to suppress rail potential.

Recent Technology Development for DC Railway Substation

Recent Technology Development for DC Railway Substation

고속전철 변전소의 고조파 분석과 대책에 관한 연구

본 논문은 고속전철 차량에서부터 변전소까지의 고조파에 대해서 분석하였으며, 수동필터를 이용한 고조파 저감 방법을 제시한다. 고속전철 변전소가 공급하는 열차구간에 있어서 운행 열차의 수에 따라 고조파의 파급 특성을 살펴보았다. 고조파는 변압기 과열과 통신유도장해 등 문제를 일으킬 수 있다. 이러한 고조파에 의한 손상을 줄이기 위하여 본 논문은 고조파 저감방법을 제시하였다. 제안된 방법은 PSCAD/EMTDC 시뮬레이션에 의해 증명되었다.

Effective Application of Superconducting Magnetic Energy Storage (SMES) to Load Leveling for High Speed Transportation System

The consecutive pulse power demand of the high speed transportation systems like Shinkansen, gives deteriorative influences to the power supply system and increases its operational costs. To cope with this problem, it has been studied to install the superconducting magnetic energy storage system (SMES) in railway substations. However, the scale of installation becomes too large because of low space factor of SMES, and hampers its realization. Then, it is considered to use SMES only for suppression of the high frequency component of load fluctuation, and to combine with a large capacity battery storage (BEMS), which can not follow fast fluctuation and covers its low frequency component. A novel control scheme of this combined energy storage system is proposed. The fluctuation of power demand caused by high speed train operations in a railway substation is measured separately in the frequency range and used to regulate both SMES and BEMS to suppress fluctuation. With simulation studies based on the load model of high speed train operation at a certain substation, this hybrid approach and its control scheme are verified effective. The system configuration is compact enough to be installed at a substation.

Low-Frequency Magnetic Field in DC Railway Substations

A measurement campaign was carried out at Orte and S.Oreste dc substations along a high-speed trunk of the Italian railway lines. The results consist of H-field values measured at the two substations, inside the buildings (near the rectifier groups) and outside (in the area surrounding the high-voltage input line, the HV/MV transformers, and the rectifier transformers) for different load conditions during normal service. The goal of this work is to determine the H-field intensity at low and medium frequency at dc railway substations. The measurement results are post-processed to extract statistical properties (namely, average values, dispersion, and distribution histograms). This information may contribute to updating and integrating standards regarding dc substation electromagnetic environment and specific immunity tests for housed equipment.

A Short-Circuit Current Study for the Power Supply System of Taiwan Railway

The western Taiwan railway transportation system consists mainly on a mountain route and ocean route. Taiwan Railway Administration (TRA) has conducted a series of experiments on the ocean route in recent years to identify the possible causes of unknown events that cause the trolley contact wires to melt down frequently. The conducted tests include the short-circuit fault test within the power supply zone of the Ho Long Substation (Zhu Nan to Tong Xiao) that had the highest probability for the melt down events. Those test results, based on the actual measured maximum short-circuit current, provide a valuable reference for TRA when comparing against the said events. The Le Blanc transformer is the main transformer of the Taiwan railway electrification system. The Le Blanc transformer mainly transforms the Taiwan Power Company (TPC) generated three-phase alternating power supply system (69kV, 60Hz) into two single-phase alternating power distribution systems (M phase and T phase) (26kV, 60Hz) needed for the trolley traction. As a unique winding connection transformer, the conventional software for fault analysis will not be able to simulate its internal current and phase difference between each phase current. Therefore, besides extracts of the short-circuit test results, this work presents an EMTP model based on the Taiwan Railway Substation equivalent circuit model with a Le Blanc transformer. The proposed circuit model can simulate the same short-circuit test to verify the actual fault current and accuracy of the equivalent circuit model.

A short circuit current study for the power supply system of Taiwan railway

The western Taiwan railway transportation system consists mainly of a mountain route and ocean route. The Taiwan Railway Administration (TRA) has conducted a series of experiments on the ocean route in recent years to identify the possible causes of unknown events which cause the trolley contact wires to melt down frequently. The conducted tests include the short circuit fault test within the power supply zone of the Ho Long substation (Zhu Nan to Tong Xiao) that had the highest probability for the melt down events. Those test results based on the actual measured maximum short circuit current provide a valuable reference for TRA when comparing against the said events. The Le Blanc transformer is the main transformer of the Taiwan railway electrification system. The Le Blanc transformer mainly transforms the Taiwan Power Company (TPC) generated three phase alternating power supply system (69 kV, 60 Hz) into a two single-phase alternating power distribution system (M phase and T phase) (26 kV, 60 Hz) needed for the trolley traction. As a unique winding connection transformer, the conventional software for fault analysis will not be able to simulate its internal current and phase difference between each phase currents. Therefore, besides extracts of the short circuit test results, this work presents a EMTP model based on a Taiwan Railway substation equivalent circuit model with the Le Blanc transformer. The proposed circuit model can simulate the same short circuit test to verify the actual fault current and accuracy of the equivalent circuit model. Moreover, the maximum short circuit current is further evaluated with reference to the proposed equivalent circuit. Preliminary inspection of trolley contact wire reveals the possible causes of melt down events based on the simulation results.

Rigorous evaluation of the voltage unbalance due to high-speed railway demands

A rigorous way of evaluating the voltage unbalance due to single-phase high-speed railway (HSR) demands on a three-phase power system is introduced in this paper. A three-phase power-flow program with simplified models of electric railway substations is adopted for rigorous studies. Various transformer connection schemes, including single-phase, V, Scott, and Le Blanc connections, are considered. The results are compared with those obtained by simple formulas that currently are commonly used to approximate the voltage unbalances. The comparison results indicate significant differences between these two approaches and emphasize that related improvement projects should be evaluated and implemented by the rigorous approach, not the simple formulas.

Calculation of remote short circuit fault currents for DC railways

The paper presents a technique for calculating the current/time profile for a remote short circuit fault at a DC rapid transit railway substation. The profile is largely determined by steel rail impedance, which is shown to vary with time within the profile. An inverse Fourier transform, employing a novel antialiasing method is applied to obtain the profile from frequency based impedance data. The technique is demonstrated to be accurate to within 10% with a comparison between a calculated profile and practically measured results obtained on a light rail system. The impedance data required in this technique can be obtained by either measurement or calculation and scaling of standard values using the method described in a companion paper.

On-line identification of the resonance conditions in the overhead supply line of electric railways

The overhead supply line of an electric railway system exhibits resonating properties at various frequencies. The eigenfrequencies are a function of the track topography. They change as traction vehicles move along the track. Electrical oscillations in the line are excited by the current harmonics of modern PWM converter-fed Locomotives. A real-time model of an extended system of railway tracks, substations and locomotives serves to study the resonance phenomena under the influence of various parameters. Further, a method is developed to identify on board a converter-fed locomotive in real-time the eigenvalues of the overhead supply system and at each eigenfrequency the actual amount of oscillating energy. The identification provides the information for possible suppression of harmonic excitation by an appropriate converter control system.

サイリスタ式電鉄変電所群の一制御方式

サイリスタ式電鉄変電所群の一制御方式

GTO DC Circuit Breaker Based on a Single-Chip Microcomputer

A single-chip microcomputer is used to obtain a versatile GTO circuit breaker for electric railway substations. The microcomputer provides firing control, excellent dc short-circuit fault interrupting performance, precise overload protection of circuit breakers by themselves, as well as high reliability with minimum components. Emphasis is on the GTO junction temperature observation.

An Application of Flywheel Energy Storage to the Electric Railway Substation

An Application of Flywheel Energy Storage to the Electric Railway Substation

A Survey of Western European AC Electrified Railway Supply Substation and Catenary System Techniques and Standards

British and Western European experience, design standards, and techniques associated with electrified railway power supply facilities are outlined. Aspects surveyed include utility supply to commercial frequency railway loads, substation design standards, catenary system design and maintenance, telecommunication and radio interference experience and suppression techniques, costs, and construction time. This survey outlines information obtained during 1967 visits with state railway, power system, and manufacturing company engineers in Great Britain, France, Germany, and Sweden. The survey confines itself to experiences and data which are believed applicable to commercial frequency (60-Hz) 25-kV electrification. A substantial part of the European railway catenary system and railway substation technology and experience outlined in the survey appears applicable to future American railway electrifications.