• Title/Summary/Keyword: Regenerative braking

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Steady State Analysis for Power System of HSR with Active Transformer

  • Kim, Wook-Won;Kim, Hyung-Chul;Shin, Seung-Kwon;Kim, Jin-O
    • Journal of Electrical Engineering and Technology
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    • v.11 no.1
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    • pp.257-264
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    • 2016
  • In this paper, new electric railway feeding system which has active transformer is modeled for evaluating the steady state analysis using PSCAD/EMTDC. Equivalent models including power supply, feeder, train and transformers are proposed for simplifying the model of the feeding system in high speed electric railway. In case study, simulation results applied to proposed model are compared with the conventional and new systems through the catenary voltage, three-phase voltage of PCC (Point of Common Coupling) and the efficiency of regenerative braking energy.

The review of the safety for the development of insulated hanger in overhead contact line (전차선로 절연 행거 개발에 대한 안전성 검토)

  • Lee, Jae-Bong;Park, Weon-Chan
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.1431-1440
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    • 2009
  • A subway in Seoul has had a major role of public transportation after the opening of Seoul Subway Line 1 on August 15, 1974 and it has reached 34.7% of the transportation of Seoul citizens. The extended length of the subway system suppled with DC power in Korea is about 500km. In this system, the devices which are proper for regenerative power system are being required because of changeover from old braking and ATS signal system to regenerative braking and ATO signal system. In this paper, we reviewed the safety standards for the insulated hangers in overhead contact line. These hangers which have depended on foreign imports are being developed in Korea considering ease of demand and supply and economic effects.

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Modelling Voltage Variation at DC Railway Traction Substation using Recursive Least Square Estimation (순환최소자승법을 이용한 직류도시철도 변전소의 가선전압변동 모델링)

  • Bae, Chang-Han
    • The Transactions of the Korean Institute of Power Electronics
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    • v.20 no.6
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    • pp.534-539
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    • 2015
  • The DC overhead line voltage of an electric railway substation swings depending on the accelerating and regenerative-braking energy of trains, and it deteriorates the energy quality of the electric facility in the DC railway substation and restricts the powering and braking performance of subway trains. Recently, an energy storage system or a regenerative inverter has been introduced into railway traction substations to diminish both the variance of the overhead line voltage and the peak power consumption. In this study, the variance of the overhead line voltage in a DC railway substation is modelled by RC parallel circuits in each feeder, and the RC parameters are estimated using the recursive least mean square (RLMS) scheme. The forgetting factor values for the RLMS are selected using simulated annealing optimization, and the modelling scheme of the overhead line voltage variation is evaluated through raw data measured in a downtown railway substation.

Characteristics of Two Phase Chopper with Two Separate Groups of DC Motors in Regenerative Braking (회생용 2분할 2상쵸퍼의 특성)

  • Han, Kyung-Hue
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.34 no.3
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    • pp.115-123
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    • 1985
  • A two phase chopper system with two separate groups of DC motors for regenerative braking is dealt with in this article. The main circuit consists of two sets of chopping parts, four diodes and two separate groups of DC motors. Although the proposed chopper circuit requires more circuit elements than the conventional two phase chopper system with combined output, it has the following advantages`(1). Ripple frequency of smoothing reactor current becomes twice as high as that of the conventional system, so the continuous current range and the ripple ratio are improved greatly. Therefore, the efficiency becomes even higher, the capacity of commutation equipment is reduced and the inductive interference become less.(2). Load current division becomes equalized. Therefore it is possible to drive not only series motors but also shunt, separately excited and compound motors.

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The Influence of Operating Conditions on Fuel Economy of the Hybrid Electric Vehicle (운전조건이 하이브리드 자동차의 연비에 미치는 영향 연구)

  • Lee Youngjae;Kim Gangchul;Pyo Youngdug
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.3
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    • pp.35-40
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    • 2005
  • In the present study, the influence of operating conditions on fuel economy for hybrid electric vehicle was analyzed. In order to accomplish this, vehicle speed, engine speed, battery current and voltage, SOC (state of charge),motor speed and torque, generator speed and torque, engine coolant temperature etc. were measured in real time. The tests were carried out under different driving cycles which are urban and highway cycles, KOREA CITY cycle and on-road driving, and also under various operating conditions such as different initial SOC, with or without regenerative braking etc.. Generally, conventional gasoline engines show a poor fuel economy at stop and go driving, because braking energy is wasted and the engine is operated in low thermal efficiency regions. However, in case of hybrid vehicles, higher fuel economy can be obtained because of utilizing the maximum thermal efficiency regions of engine, idling stop of engine, and regenerative braking etc..

A Study on Application Method of Brake System Modular Design for Medium and Large EV Architecture (중형 및 대형 EV 아키텍처를 위한 제동시스템 모듈러 설계 적용 방안에 관한 연구)

  • J. H. Shim;S. R. Hwang
    • Journal of Auto-vehicle Safety Association
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    • v.16 no.1
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    • pp.21-28
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    • 2024
  • Many global car manufacturers in the world are recently developing a variety of electric vehicles in response to demanding market needs. Also, they have adapted the architecture method in order to develop electric vehicles effectively. It is because architecture method can produce various electric vehicles with high profitability. However, when electric vehicles are being developed, brake system has a lot of demanding tasks in relation to deciding specification of brake system because of heavy vehicle weight, narrow power electric room space and large volume of electric hydraulic booster. In this paper, a new approach is proposed for deciding the front and rear brake systems in order to design the brake system of electric vehicles effectively. To do this, we study correlations among vehicle weight, layout of power electric room and volume of electric hydraulic booster. And then, we also study combination of hydraulic braking and regenerative braking which is widely applied to electric vehicles. Finally, we want to contribute to build up modular design of brake system for architecture of electric vehicles through these studies.

Design and Control of Braking Chopper Circuit for Ventilation Inverter of Traction Control System (고속전철용 추진제어장치의 냉각용 인버터를 위한 제동초퍼 회로 설계 및 제어)

  • Cho, Sung-Joon
    • Proceedings of the KIPE Conference
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    • 2011.07a
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    • pp.314-315
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    • 2011
  • This paper introduces the design and control method of braking chopper circuit which can supply input power to ventilation inverter of traction control system. The DC input voltage from auxiliary block (static inverter) is normally used as an input of ventilation inverter. It converts DC input to AC output voltage to drive cooling fans for traction control system and traction motors. The electrical braking force is very important for high speed train to guarantee safety even though the train is running in the dead section where the pantograph voltage is not supplied. When the high speed train decelerate speed in dead section, the regenerative energy is dissipated by braking resistor. This paper proposed the braking chopper control method to implement rheostatic braking function and the appropriate chopper circuit for supplying voltage source to ventilation inverter during rheostatic braking mode. The proposed chopper circuit makes it possible for traction control system to regenerate power continuously regardless of the existence of pantograph voltage. The feasibility of proposed braking chopper control and circuit were proven by inertia load test and actual train field test.

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