• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.12
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• pp.868-873
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• 1987

In this pater, we have proposed a synthetic main chopper circuit for the chopper controlled electric automobile. The proposed chopper circuit operates as a step-down chopper in powering mode and as a polarity reversion type chopper in regenerative braking mode. In this study, it was found that powering and regenerative braking operations using the separately excited D.C motor can be controlled continuously only by gate signals of the chopper without changing the connection of the circuit.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.4
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• pp.349-356
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• 1990

In order to control DC motors for electric cars by chopper system, four quadrant operations - forward powering, forward regenerative braking, reverse powering, reverse regenerative braking - are needed. For the four quadrant operations, the separately - excited DC motors are used in this study. The conversion of each quadrant operation has been obtained by 1) adopting the two phase chopper system with combined output for the armature control, and 2) the single phase chopper system for the field control.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.717-722
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• 2007

Most of DC 1500V electric railway substations have adopted diode rectifiers to supply stable DC power. However, the diode rectifiers operate in the first quadrant of the voltage-current plane and thus need regenerative inverters which transfer the surplus regenerative power caused by regenerative braking of electric train sets into the grid. In order to select the proper capacity and installation position of regenerative inverter, it needs to investigate the consumed and regenerative energy of the electric traction substations in advance. This paper presents an analysis of regenerative energy in two substations operating in Seoul Seolleung and Kwangju Yangdong substations. DC line voltage and feeder currents are measured for a day to calculate consumed and regenerative power far four feeders. We calculated an amount of regenerative energy consumed in other feeders and estimated the cost reduction in energy consumption due to the reuse of regenerative energy

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.269-271
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• 2004

In this study, on-line measuring system were developed to verify performances and characteristics of electric braking system that is used in KTX(Korea Train eXpress) synthetically and efficiently Because KTX is commercial vehicle, effective measurement and evaluation of measuring signals were performed beyond the range of change for equipment components. KRRI(Korea Railroad Research Institute) described about running-braking measuring program, running-braking backup program and running-braking analysis program that were developed using a software called LabVIEW in this paper. Also, we analyzed the characteristics comparing experimental values with design values about braking distance, braking time, negative acceleration and braking effort in rheostatic braking and regenerative braking. In result, main performances and characteristics for electric braking system in KTX were verified.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.580-585
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• 2003

Korean high speed train (KHST) has adopted a combined electric/ mechanic (friction) braking system. Electric brakes are consist of rheostatic brake, regenerative brake and eddy current brake and mechanical brakes are composed of disc brake, wheel disc brake and tread brake. In this paper, we introduce the braking performance test and the measuring method of mechanical brake. And disc brake performance has been reviewed by the experimental method. The on-line test of KHST has been carried out up to 260 km/h and proved that the disc braking capacity of KHST is sufficient.

• Journal of Power Electronics
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• v.11 no.2
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• pp.120-131
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• 2011

This paper proposes two control strategies for the bidirectional Z-source inverters (BZSI) supplied by batteries for electric vehicle applications. The first control strategy utilizes the indirect field-oriented control (IFOC) method to control the induction motor speed. The proposed speed control strategy is able to control the motor speed from zero to the rated speed with the rated load torque in both motoring and regenerative braking modes. The IFOC is based on PWM voltage modulation with voltage decoupling compensation to insert the shoot-through state into the switching signals using the simple boost shoot-through control method. The parameters of the four PI controllers in the IFOC technique are designed based on the required dynamic specifications. The second control strategy uses a proportional plus resonance (PR) controller in the synchronous reference frame to control the AC current for connecting the BZSI to the grid during the battery charging/discharging mode. In both control strategies, a dual loop controller is proposed to control the capacitor voltage of the BZSI. This controller is designed based on a small signal model of the BZSI using a bode diagram. MATLAB simulations and experimental results verify the validity of the proposed control strategies during motoring, regenerative braking and grid connection operations.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.342-345
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• 1997

To achieve adequate brake performance in high-speed trains the brake system should : ${\bullet}$ offer high reliability and high availability, ${\bullet}$ permit deceleration of the train with as little wear as possible, and ${\bullet}$ display good control characteristics with, if possible, infinitely variable control of the braking effort. For these reasons, high-speed train is to be equipped with three different and largely independent brake system : ${\bullet}$ a regenerative brake with regenerative feedback in the driven cars, ${\bullet}$ a linear eddy-current brake in the nondriven cars and ${\bullet}$ a pneumatic disc brake in all cars. This paper describes the conceptual design of braking system for Korea High Speed Train with the maximum speed of 350km/h

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.544-551
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• 2011

This paper presents the circuit arrangement and effective control method of regenerative energy storage system for an electric vehicle using super-capacitors as the braking energy storage element. A bi-directional controlled current flow of the DC-DC converters with the capacitor bank is connected in parallel with battery, and is controlled so that the whole of the braking energy is effectively absorbed into the capacitors and released back to the electric motor upon acceleration. The converter needs the series-parallel switching circuit for making the best use of the series capacitors and for limiting the step-up ratio of the boost converter. The proposed methods are verified by computer simulation and experimental set-up. They are usefully applied to the electric vehicles such as green cars, electric motorcycles, bike, etc which are power- supplied by the electric batteries.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.407-408
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• 2017

In regenerative mode of an IPMSM control system without a bi-directional DC-DC converter, the 3-phase PWM inverter charges the battery. At this time, the regenerative torque reference for braking must output the proper torque reference to charge the battery. This paper proposed a regeneration control method that controls the voltage and current of the battery through CC-CV control at the regenerative braking torque corresponding to the driver's brake control.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.836-845
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• 2007

In DC 1500V electric traction substations, diode rectifiers are commonly used to supply stable DC power with electric train sets. However, it operates in the first quadrant of the voltage-current plane and thus needs regenerative inverters which transfer the surplus regenerative power caused by regenerative braking of electric train sets into the grid. In order to select the proper capacity and installation position of regenerative inverter, it needs to investigate the consumed and regenerative energy of the electric traction substations in advance. This paper presents an analysis of regenerative energy in two substations operating in Seoul line 2 and Kwangju line 1. DC line voltage and feeder currents are measured for a day to calculate consumed and regenerative power for four feeders. We calculated an amount of regenerative energy consumed in other feeders and estimated the cost reduction in energy consumption due to the reuse of regenerative energy.