Gildong Kim

A Study on the Effects of Energy Storage System

The energy storage system creates optimum conditions for energy regeneration in urban transit systems. The energy storage system is able to store and discharge energy at an extremely rapid rate. This enables a complete exchange of energy between vehicles, even when they are not braking and accelerating at precisely the same time, as is most frequently case in everyday service. The benefits of the energy storage system include energy savings and voltage stabilization. Energy storage systems are generally installed for the purpose of saving energy. However, energy storage systems are sometimes applied in order to stabilize voltage. This paper presents the energy storage system applied for the purpose of voltage stabilization. In this case, the system still saves a small amount of energy. This energy savings, coupled with the system’s ability to reduce CO2 emissions, will contribute greatly to environmental preservation efforts.

Field Tests of DC 1500 V Stationary Energy Storage System

The ESS(energy storage system, here after) for a DC 1500V was developed in 2009. A ESS was installed on the track of Daejeon HRT in 2010. The advantage of the ESS is that it can save the energy and plus stable the catenary voltage. This paper presents the energy saved by the ESS in Daedong substation. When the ESS is on/off, the field tests are performed.

A study on management system for reliability analysis in advanced EMU

Advanced Emu consist of a 6-car production was completed. Advanced EMU has been performed to verify the reliability, safety and so on. We built the PDM with system engineering technology. We constructed the management system in PDM for failure history data and analyzed the reliability of advanced EMU.

Reliability Analysis of New Type Electric Multiple Unit

New type of Electric Multiple Unit (EMU) so called advanced EMU has been developed to improve reliability, safety, maintainability, energy efficiency and environmental friendship. The following new technology and subsystem are developed and adopted to the EMU. Direct Drive Motor (DDM), plug-in door, sliding step, wide gangway, electric braking system, single arm pantograph, individual motor control system and passenger information system. Since the new developed system influences to the RAMS(Reliability, Availability, Maintainability, Safety) factor, we suggest new reliability target and reliability prediction plan to design and develop Advanced EMU. After that, reliability demonstration will be processed by testing the system on the specific test line to review RAMS prediction and enhance reliability of advanced EMU. This paper represents the reliability prediction and demonstration procedure to apply to the advanced EMU based on the referenced RAMS standards.

A Study on the Equivalent Conductor Representation of AC Electric Railway System

This paper presents the equivalent conductor representation of AC electric railway systems. Since the fault current flows through the catenary system, the catenary system must be modeled exactly to analyze fault current magnitude and fault location. In this paper, the equivalent conductor modeling technique that includes boost wires and impedance bonds is introduced, based on the characteristics of AC electric railway. After obtaining the equivalent conductor modeling, the railway system is constructed for computer simulation by using PSCAD/EMTDC. Studies for fault current are carried out by the proposed model.

A Study on the Application of ESS on SeoulMetro Line 2

The energy storage system in urban transit systems is able to store and discharge energy at an extremely rapid rate. This enables a complete exchange of energy between vehicles, even when they are not braking and accelerating at precisely the same time, as is most frequently case in everyday service. The energy saving rate is related to the headway. If the headway is long/short, the energy saving goes up/down. When the headway is long, the ESS can save a lot of regenerative energy. The headway of SeoulMetro line 2 is very short in Korea urban transit system. So, the energy saving rate will be very low. If the ESSs are applied to another railway system, we expect that the effectiveness is better than the results of SeoulMetro line 2. This paper presents effects of energy saving and reduction of the CO2-emission by applying the ESS to SeoulMetro line 2.

Optimal Capacity of SVC to Compensate Flicker Induced by Electric Arc Furnace

Electric arc furnaces are one of the most severe sources to induce voltage flickers and hard to make an analysis model due to its chaotic characteristics. In this paper, a practical modeling strategy for electric arc furnaces is suggested. By using this model, the flicker phenomena induced by electric arc furnaces are simulated and analyzed to find out solutions for compensation. To compensate voltage variation and frequency fluctuation, we used SVC devices and suggested a novel scheme to identify the optimal capacity of SVCs by using Pst flicker index which is suggested on IEC standards.

Safety criteria and development methodology for the safety critical railway software

The main part of the system is operated by the software. Besides the safety critical system such as railways, airplanes, and nuclear power plants is applied by the software. The software can perform more varying and highly complex functions efficiently because software can be flexibly designed and implemented. But the flexible design makes it difficult to predict the software failures. We need to show that the safety critical railway software is developed to ensure the safety. This paper is suggested safety criteria and software development methodology to enhance safety for the safety critical railway system.

Management system of advanced EMU using PDM

The advanced EMU has been developed the core technologies. The advanced EMU consists of a 6-car. The advanced EMU has been performed to verify the reliability, safety and so on. This paper developed PDM(product data management) to make a system engineering of the advanced EMU.

Development and characteristics of bogie unit braking system for EMU

We have been developed the bogie unit braking system. In the braking process of rolling stocks, the equivalent braking force is applied to the all bogies. However, the load applied to the front and rear bogie are different in the actual commercial traveling. In the case, since the different slip situation is occurred in each bogie, it is essential to use the independent anti-slip control per bogie unit in order to reduce the loss of braking force. This paper describes the functions and characteristic of the bogie unit braking system.