Mobile QR Code QR CODE : The Transactions of the Korean Institute of Electrical Engineers

방열 제약과 온수공급 계통구성을 고려한 기반 열병합발전기 최적 운전 알고리즘 개발 A Particle Swarm Optimization for Combined Heat and Power Operation Considering Heat Extraction and Network Constraint

https://doi.org/10.5370/KIEE.2020.69.10.1415

김태형(Taehyoung Kim) ; 임정택(Jeongtaek Lim) ; 함경선(Kyung Sun Ham) ; 서재완(Jaewan Suh)

Distributed combined heat and power(CHP) is considered as a solution to the centralized power system congestion and the carbon emission. However, since small-scale CHPs are not economically viable, advanced operation method is needed. This paper proposes particle swarm optimization with adjacency matrix and heat extraction constraint for optimal CHP operation. We made nonlinear CHP output model from demonstration data. Mesh and Non-mesh hot water network case is simulated by MATLAB 2019a for a day operation. Simulation results are compared to case without heat extraction constraint and showed the effectiveness of the proposed method.

환경비용과 전력거래요금 차이를 고려한 한 중 계통 연계선로 경제성 분석 Economic Analysis of Korea-China Interconnection Power Line Considering Both of Environmental Cost and the Differences of Power Transaction Cost

https://doi.org/10.5370/KIEE.2020.69.10.1426

정희원(Hui-Won Jeong) ; 차준민(Junmin Cha) ; 이규섭(Gyu-Sub Lee)

The Northeast Asia Super Grid, a large-scale power line interconnection project in Northeast Asia, is being reviewed in the second half of 2017. As a result, there is increasing interest in research on the feasibility of interconnection between countries. Prior to the interconnection business, reviewing the technical and economical analysis is an essential process. This paper is based on the review of technical feasibility in 2016 on the interconnected between Korea-China to submarine cable. There is based on the result of the technical feasibility of the shortest distance (380 km) of submarine cable among several Korea-China interconnection sites of previous studies. The Interconnection between Korea and China is configured by HVDC ±500kV submarine cable. The following three variables are considered to construct the scenario and analyze the economic feasibility :  reduction effect, power price uncertainty of both countries, economic comparison with additional power plants. For the analysis, we use the four indices NPV (Net Present Value), IRR (Internal Rate of Return), B/C ratio(Benefit-Cost ratio) and CRP(Cost Recovery Period). The economical analysis of these scenarios are shown in this study.

변전소의 새로운 고장유형 판별 및 고장복구 시각화 A Novel Fault Type Identification and Fault Restoration Visualization for Substation

https://doi.org/10.5370/KIEE.2020.69.10.1432

이경민(Kyung-Min Lee) ; 홍재영(Jae-Young Hong) ; 강태원(Tae-Won Kang) ; 박철원(Chul-Won Park)

Recently, the 4th industrial revolution is affecting industry and society as a whole. Accordingly, the need for autonomous intelligence of substation and power grids is being raised through artificial intelligence technology. This article, as part of the results of basic research on a fault restoration plan using intelligent techniques for digital substations, studied on a novel fault type identification and fault restoration visualization of the 154kV substation using the deep neural network and expert system. We constructed learning data through the operation status information such as CB and relay of transmission line, bus, transformer, and distribution line, which are components of the substation, and identified 15 fault types through deep neural networks. And the implemented system outputs a fault recovery procedure of the determined fault type through the expert system. Finally, we performed 4 fault types simulations to verify the performance of the fault restoration visualization

발전소 고압배전계통 계기용변압기 손상 메커니즘 및 대책 Analyze the Root cause of a VT Fuse and Suggest the Solution

https://doi.org/10.5370/KIEE.2020.69.10.1440

김순용(Soon-Yong Kim) ; 박진엽(Jin-Yeub Park) ; 정필범(Pil-Bum Jeong)

Power Fuses that are installed to protect for Voltage Transformer had been burnt out by operating environments, the characteristic of fuse and aging in power plants. To analyzes the root causes of fuse failures, this study reviews the appropriateness of the fuse selection according to the VT rating and capacity, the effects of inrush current that may occur during VT power up and the possibility of resonance due to poor VT excitation characteristics. In addition, the internal condition and the blown-off melt shape of the burned-out fuse were confirmed by the industrial X-ray, the electron microscope, and the material analysis.

ESS / BESS 지 단락 실증시험에 기반한 고장모의 해석 Battery ESS Fault Analysis based on the ESS Ground/Shortcircuit Test

https://doi.org/10.5370/KIEE.2020.69.10.1445

김수열(Soo-Yeol Kim) ; 임지훈(Ji-Hoon Im) ; 이일용(Il-Yong Lee) ; 김진태(Jin-Tae Kim) ; 최인규(In-Kyu Choi) ; 김형근(Hyeong-Geun Kim)

Battery ESS had been variously applied to power grid before recent ESS fires in Korea. An investigation committee was constituted to find fire causes and countermeasures to ESS fires. The investigation committee has identified top 4 causes for recent ESS fires as insufficient battery protection system against electric faults, incomplete system integration, inadequate management of operating environment, and careless installation. And recent 2nd investigation committee has presumed that battery abnormal condition was another reason for ESS fires. Battery protection system and system integration could be related with systematic issues such as insulation and protection coordination between PCS and battery system, information sharing and protection sequence. Manufactures made their best efforts to upgrade PCS and battery system by each, but had no much interest in the other subsystems of integrated system except their owns. Systematic analysis is very important to improve the reliability of ESS, which is combined by AC source and DC source via PCS. This paper reports system analysis results and suggests countermeasures against electrical faults, including simulation of ground fault and short fault, demonstration test result and systematic issues more than anything to solve for ESS business going forward.

영구자석 동기전동기의 파라미터에 따른 오프라인 고장진단 특성에 대한 연구 Study on the Offline Inter-turn Fault Diagnosis According to the Parameter of Permanent Magnet Synchronous Motor

https://doi.org/10.5370/KIEE.2020.69.10.1456

김현우(Hyunwoo Kim) ; 박예지(Yeji Park) ; 오승택(Seoung-Taek Oh) ; 장형관(Hyungkwan Jang) ; 배재남(Jae-Nam Bae) ; 이주(Ju Lee)

This paper analyzes the characteristic of an inter-turn fault diagnosis according the parameter of permanent magnet synchronous motor (PMSM). If the inter-turn fault occurs in PMSM, the d-axis current is different from the d-axis current in the healthy condition. Through the difference between the d-axis current in the healthy and faulty condition, the inter-turn fault can be detected. Consequently, the magnitude of the d-axis current determined the characteristic of the inter-turn fault diagnosis. The offline diagnosis was performed by applied voltage into the PMSM. The performance of the offline diagnosis depended on the parameter of the PMSM. Thus, the performance of the offline diagnosis was analyzed according parameter of the PMSM that is fault resistance, winding resistance and saliency ratio. In addition, to verify analytical method, inter-turn fault diagnosis is performed by co-analysis that was the link between the finite element analysis (FEA) and the control simulation tool.

컨버터 구동용 전동기 효율 측정을 위한 규격에 관한 연구 A Study on the Standard for Measuring of Converter Fed Motor Efficiency

https://doi.org/10.5370/KIEE.2020.69.10.1464

장기봉(Ki-Bong Jang)

Efforts to reduce energy consumption and carbon dioxide emissions continue to be made to cope with growing climate change and environmental problems. To this end, improving the efficiency of the motor has become an important part. Regulations on the efficiency of electric motors around the world continue to increase, and in recent years, the efficiency of the converter-fed electric motor has also been included in the regulation. In Korea, only the efficiency of electric motors operated directly by grid is subject to regulation. However, it is expected that it will gradually expand into a converter-fed motor. In this regard, KSCIEC 60034-2-3 was also established in Korea in 2019 as a standard for measuring the efficiency of converter-fed motor. In this paper, the current status of the international standard related to the efficiency measurement of electric motors and the domestic standard corresponding thereto are reviewed.

전산모사 시뮬레이션을 이용한 에서의 Laterally Diffused MOS(LDMOS) Displacement Defect의 영향 Impact of Displacement Defect on Laterally Diffused MOS (LDMOS) using Numerical Simulation

https://doi.org/10.5370/KIEE.2020.69.10.1470

김정식(Jungsik Kim)

The effect of displacement defect due to radiation effect is investigated in laterally diffused metal oxide semiconductor (LDMOS) using technology computer-aided design (TCAD) simulation. The displacement defect with acceptor-like trap of deep level (Ec-0.4eV) under shallow trench isolation (STI) induces the worst degradation of Id-Vg characteristic. The location of defect under STI with lightly doping concentration is the worst position to transfer characteristic of Id-Vg. For breakdown voltage characteristic, the positions and types of displacement trap are negligible, because of high drain voltage operation.

불확실한 시변 무게 및 외란을 가진 쿼드로터의 -슬라이딩 평면을 이용한 호버링 제어 Hovering Control Using -sliding Surface of Quadrotor with Uncertain Time-Varying Mass and External Disturbance

https://doi.org/10.5370/KIEE.2020.69.10.1474

엄영철(Yeong-Cheol Um) ; 최호림(Ho-Lim Choi)

In this paper, we propose a feedback controller using sliding surface for quadrotor with uncertain time-varying mass and external disturbance. For the robust hovering control of quadrotor, we using sliding surface and analyze the closed-loop system using Lyapunov function. Through analysis, we show that  can reduce the ultimate bound of each state. In addition, the proposed controller is applied to the actual quadrotor to illustrate the validity of the proposed controller.

회전자 위치검출 신호 펄스 폭 가변제어를 통한 BLDC 전동기 구동 제어 Pulse Width Variable Control of Rotor Position Detection Signal for BLDC Motor Driving Control

https://doi.org/10.5370/KIEE.2020.69.10.1484

정성인(Sung-In Jeong)

In general, in order to control the stator current and angle, high-precision rotor position information is required due to the characteristics of the BLDC motor. Since this information is used by connecting a position sensor such as an encoder or resolver to the rotating shaft of the motor, it is a factor that increases the size of the device, the cost of the driving system, and the inertia of the rotor. Another method for obtaining the rotor position information is to detect the position by the Hall-sensor and attach it to the part corresponding to the magnetic axis of the stator winding, and the rotor position information corresponding to the electric angle of 60 is in 6 steps. Can be obtained by stator exciting. It is difficult to maintain the motor at a constant speed because this ? method generates torque ripple and cannot be precisely controlled by feedback. Therefore, based on these problems of the position sensors, many methods of driving the BLDC motor by sensorless have been studied, but basically, the initial driving and the driving at low speed of the motor act as a big problem. Therefore, in this paper, we aim to improve the low-resolution problem by constructing a circuit that can replace a high-speed sensor such as an existing encoder or resolver using a low-cost Hall sensor. In this process, in the case of a BLDC motor with a low-speed specification, 1) the existing 6-pulse signal cannot be recognized, 2) the required time for the pulse-width of the 6-pulse signal, and 3) since the problems such as the required time for the pulse width of the signal and 3) since problems such as the complexity of a circuit composed of hardware are considered, we will study the method of driving a BLDC motor through variable control of the pulse width of the proposed rotor position detection signal

220 nm 대역의 아크광 검출을 위한 교정시스템 구현 An Implementation of Calibration System for Arc Detection in 220 nm UV Light

https://doi.org/10.5370/KIEE.2020.69.10.1490

나경민(Kyung-Min Na) ; 이기원(Kiwon Lee) ; 박철민(Chul-Min Park) ; 박영(Young Park)

The demand for renewable energy equipment and power equipment for use in electric railways has been increasing owing to the expansion of dispersed power sources and urban railroads. Arc flashes occur because of insulation breakdown, leakage, and contact loss, and it may cause electric fires in DC power equipment. Arc flashes are detected by temperature, pressure, acoustic, light, and electrical methods. The photosensor detection is a noncontact method but has the disadvantage of high external noise owing to sunlight depending on the wavelength band from among these. An arc detector in the 220-nm ultraviolet (UV) light is developed to reduce noise and is not affected by sunlight. However, there is no prior research on the deterioration of electrical equipment when using arc discharge. Therefore, correcting errors, such as light density, generation time, and distance, through arc flash replay is necessary to determine the deterioration of DC power equipment. In this paper, we propose a calibration system for reproducing an arc flash in the 220-nm UV light. The calibration system comprises a 150-W light source and a xenon-series chopper disc, and the result of the photosensor response to 220-nm UV light is noted.

철도 전철 부품의 스마트 제조기술 기초연구 A Basic Study on Digital Manufacturing Technologies for Catenary System in Railway

https://doi.org/10.5370/KIEE.2020.69.10.1495

최균석(Kyunsuk Choi) ; 김주욱(Joo-Uk Kim) ; 이기원(Kiwon Lee) ; 서경주(Kyoung-Ju Seo) ; 박영(Young Park)

Recently, smart manufacturing technology research is being conducted in various fields, using digital parts-based technologies. Components that are used for electrification in electric railways are manufactured using casting techniques. This is because the mechanical and electrical properties required to ensure safety considerably vary, and the standards defined for errors are strict. To apply digital parts-based manufacturing technology to parts for electrification, the design of existing parts must be 3D-modelled, and research must be conducted on manufacturing techniques using metals. In this study, we investigated digital laminate manufacturing technology for smart manufacturing of parts for electrification. The clevis-type terminal clamp of the contact wire was manufactured using stereolithography apparatus. The deviation, which was measured using a 3D hybrid scanner and a 3D coordinate measuring device, was observed to be approximately ± 500 m. The model illustrated in this paper will be used as a reference to study metal μ train parts in the future. In addition, it is expected to be used as a pre-modelling development technology for manufacturing singular-shaped parts

타 귀선전류 영향에 따른 급전계통 단권변압기 보호에 관한 연구 A Study on the Protection of the Auto Transformer according to the Influence of Return Current on Adjacent Line at Feeding System

https://doi.org/10.5370/KIEE.2020.69.10.1499

이동호(Dong-Ho Lee) ; 최용은(Yong-Eun Choi) ; 박원찬(Weon-Chan Park) ; 김재문(Jae-Moon Kim) ; 강정원(Jeong-Won Kang)

When a ground fault by contact wire or feeder occurs on the AT feeding system, the return current on adjacent lines resulted by a ground fault effect on considerable shock to the AT on the normal feeders, but does not protect the AT from excessive return current on adjacent lines. AS a result, in extreme cases, the AT is burned, causing a secondary feeding failure due to a power supply failure in the up and down lines. In this paper, we proposed the installation of an overcurrent relay(OCR) to protect the AT from the return current on adjacent lines. By means of the OCR, the magnitude of the return current was checked, and circuit breaker(CB) was cutoff on the healthy phase at the measurement of the return current on adjacent lines exceeding more than 7 times of rated current of AT. Through this study, it is expected that the reliability of the power supply system will be improved by preventing not only the shock on the healthy AT but also secondary accidents.

AT 흡상전류 분배비를 활용한 교류철도 분기선로에서의 고장구간 판별기법 평가 An Evaluation of Fault Zone Discrimination Technique Using Real Time AT Absorbing Current Distribution Ratio in AC Railway Branch Line

https://doi.org/10.5370/KIEE.2020.69.10.1504

정호성(Hosung Jung) ; 신승권(Seungkwon Shin) ; 김형철(Hyungchul Kim) ; 김길동(Gildong Kim) ; 민명환(Myung-Hwan Min) ; 안태풍(Tae-Pung An)

This paper presents a fault zone discrimination and more accurate fault location estimation technique in the AC railway system with a branch line. For this, we propose fault zone discrimination technique using real time AT absorbing current distribution ratio and fault location estimation technique using all AT absorbing current in the branch line. And, we also consider another line's AT absorbing current characteristics to calculate fault location. In order to evaluate the performance of the proposed technique, we test low voltage artificial forced short fault between traction line and rail in real operation branch line. As a field test result, we verify that each AT absorbing current distribution ratio index is constant to each fault zone. And, we model the AC traction power supply system with a branch line using power analysis program(PSCAD/EMTDC) to evaluate fault estimation error of the proposed technique. As a simulation result, when comparing the error of the conventional technique and the proposed technique, the conventional technique shows maximum 0.475km(4.39%) in the main line and maximum 1.727km(12.10%) in the branch line. However, the proposed technique shows under 1.0% error in all fault zone, which is satisfied within 2% of the domestic standard.

PSCAD 모델링을 통한 교류철도계통 전압불평형 보상 장치의 유효성 분석에 관한 연구 A Study on the Validity Analysis of Voltage Unbalance Compensation Devices in the AC Railway System through PSCAD Modeling

https://doi.org/10.5370/KIEE.2020.69.10.1512

고유란(Yu-Ran Go) ; 김현우(Hyun-Woo Kim) ; 민명환(Myung-Hwan Min) ; 안태풍(Tae-Pung An) ; 이태훈(Tae-Hoon Lee)

In AC railway system using single phase power, voltage unbalance for three phase is one of power quality issues. Voltage imbalance affects the life and efficiency of power facilities and devices that receive power from the same three-phase power system. Special transformers are applied to improve these problems, but it does not solve voltage imbalances completely. In this paper, we present the equation of voltage unbalance factor in system applied with scott transformer based on voltage unbalance factor defined in IEC standard. It then used actual measurement data to analyze the voltage unbalance characteristics. And the modeling for AC railway system, voltage unbalance compensation devices similar to actual site and are performed using PSCAD. The simulation was also performed by load modeling with actual measurement data. Through this, the validity of the improvement of the voltage unbalance using the compensation device is analyzed.

실용화 측면에서의 전기철도계통과 스마트 부하 밸런싱 시스템의 인터페이스에 관한 연구 Study on the Interface of Electric Railway System and Smart Load Balancing System in the Aspect of Practical Use

https://doi.org/10.5370/KIEE.2020.69.10.1519

정노건(No-Geon Jung) ; 박진규(Jin-Kyu Park) ; 김상헌(Sang-Hun Kim) ; 장홍석(Hong-Seok Jang) ; 최성수(Seong-Soo Choi) ; 이태훈(Tae-Hoon Lee)

In this paper, the interface that should be considered for the smart load balancing system to be practical. For this, an electric rail power supply system and a smart load balancing system were modeled, and the interface characteristics were analyzed by combining them and simulating them. For the load, a resistances of 11.60MVA similar to that of a general railroad vehicle and a load of 7.56MVA that can occur while a railroad vehicle is running were used. As a result, it was confirmed that the voltage difference on the M/T may vary depending on the connection position of the load and the measurement position(SSP, SP). And it was confirmed that the voltage difference occurred differently according to the load size(11.60, 7.56MVA) too. And for the practical use of the smart balancing system, it was confirmed that optimal design of hardware, controller, etc. is necessary in consideration of all situations analyzed in this paper.

고무차륜 강체전차선에 해빙 루프 전류 인가 시 온도상승 예측 연구 A Study on Prediction of Temperature Increase when Applying De-Icing Loop Current in the Rigid Conductor of AGT 3rd Rail System

https://doi.org/10.5370/KIEE.2020.69.10.1525

권삼영(Sam-Young Kwon) ; 박기현(Ki-Hyun Park)

This paper aims to review the basic conditions in designing the de-icing system of the loop current type in AGT 3rd rail system. The loop current type is defined as melting ice/frost on the rigid conductor by Joule’s heat generated by large current flowing through rigid conductor. A simulation is more cost-, time- effective means than experiments in reviewing the temperature increase in loop current type of de-icing system. To make simulation program, the theoretical backgrounds were reviewed. In accordance with the established theory, simulation program was written in MS-Excel. To verify the accuracy of developed simulation program, current injection experiments in rigid conductor were conducted. Temperature rises at 1700A, 1500A, 1200A were compared with the program. Two(experiment and program) results were fairly good agreed. With the simulation program, case studies were conducted in various assumed conditions, especially in 2m/s wind condition and in 60 minutes current injection, etc. From simulation case study, we deduced followings; 1) The operation of loop current de-icing system is quite safe up to 1700A-60 minutes current injection condition. 2) 30 minutes before commercial operation is proper for the current injection time 3) To obtain the de-icing effectiveness, it is necessary to inject the 1500A or more.

직류철도 전압 안정화를 위한 및 신재생에너지 적용 연구 Study of Voltage Stabilization on DC Railway Using Renewable Energy Source and Energy Storage System

https://doi.org/10.5370/KIEE.2020.69.10.1533

윤치명(Chi-Myeong Yun) ; 조규정(Gyu-Jung Cho) ; 김주욱(Joo-Uk Kim) ; 김형철(Hyungchul Kim) ; 김철환(Chul-Hwan Kim) ; 정호성(Hosung Jung)

Some of the Countries use DC 3kV for railroad electrification system. However, due to operational problems of electricity suppliers, unstable power is inevitable among some countries. For stable railroad operation, measures to solve the power shortage problem of electricity supplier are needed. Main purpose of this paper is to bring voltage stabilization under power shortage on DC railway system using Energy Storage System(ESS) and Renewable Energy Sources(RES). In order to supply the power shortage, 1MW Photovoltaic(PV) power plant is considered. By monitoring the catenary voltage, an algorithm capable of stabilizing the DC railroad voltage according to the voltage fluctuation of the power supplier is presented. Based on proposed algorithm, modeling was performed using the power system analysis program, PSCAD/EMTDC to verify. In addition, this paper makes various assumption of the voltage variations in order to check whether ESS and RES can stabilize the voltage.

OpenDSS를 이용한 국내 전기철도 급전계통 모델링 Modeling of Domestic Electric Railway Feeding System using OpenDSS

https://doi.org/10.5370/KIEE.2020.69.10.1540

조규정(Gyu-Jung Cho) ; 신승권(Seung-Kwon Shin) ; 정호성(Hosung Jung) ; 김주락(Joorak Kim) ; 김재원(Jaewon Kim) ; 김형철(Hyungchul Kim) ; 김철환(Chul-Hwan Kim)

Commercial Electomagnetic Transient Programs show accurate transient results by solving differential equations with respect to the circuit, but are not suitable for fast, data-based analysis. The open source distribution simulator is an open program developed for planning and analysis of the distribution system, and provides a strong linkage function with external programs and fast processing speed. In this paper, a process of modeling through an open source distribution simulator was proposed by considering the double-track parallel feeding system applied to the domestic high-speed railway system as a representative. The proposed modeling method was verified by simulating the target system under the equal conditions with a transients program and comparing the results. Modeling and utilizing the railway system through flexible and simple text-based open software can contribute to future artificial intelligent-based analysis, or energy efficiency in terms of operational aspects.

철도역사용 유도등에 적용되는 플라이백 컨버터 LED 역률개선에 관한 연구 A Study on the Flyback Converter Power Factor Correction Applied to LED Exit Lights for Railway Stations

https://doi.org/10.5370/KIEE.2020.69.10.1548

오효석(Hyo-Seok Oh) ; 김민섭(Min-Seop Kim) ; 심규석(Kyu-Seok Shim) ; 장진영(Chin-Young Chang) ; 김재문(Jae-Moon Kim)

In this paper, a simple method to improve the power factor of the conventional LED exit light with a flyback converter was proposed. Conventional flyback converters are applied to LED exit lights, which are constant loads, and 4.8[V] batteries are connected in parallel at the output stage. Therefore, by adding a passive filter between the rectifier circuit part and the primary side of the transformer, it is possible to minimize the change of the conventional circuit and improve the power factor. As a result of changing the duty ratio of the flyback main switching device from 25% to 56%, the power factor showed a high result from 95.5% to 98.3%.

철도 분기기의 설빙 방지를 위한 유도방식 히팅 장치의 특성 분석 연구 Study on Characteristic Analysis of Induction Type Heating Device for Anti-icing in Railway Switch

https://doi.org/10.5370/KIEE.2020.69.10.1555

정거철(Geochul Jeong) ; 지우영(Woo-Young Ji) ; 김진출(Jin-Chul Kim) ; 박찬배(Chan-Bae Park) ; 이재범(Jae-Bum Lee) ; 이주(Ju Lee) ; 이형우(Hyung-Woo Lee)

In this paper, a study was conducted on an induction type heating device to remove snow and ice that may cause obstacles and malfunctions of the railway switch. In the induction heating device, an ohmic loss is the heat source. Ohmic loss and heat transfer change greatly depending on the shape and material of the heating device and condition of the atmosphere. Since the loss must be accurately calculated to conduct the thermal analysis properly, it is necessary to analyze the electromagnetic and thermal characteristics and to interlock of electromagnetic and thermal analysis. Therefore, the electromagnetic and thermal analysis was conducted using finite element method (FEM). By the performance test of the prototype, verification of the simulation was conducted.

고신뢰성 보조전원장치 개발을 위한 신뢰성 평가에 대한 연구 A Study on Reliability Evaluation for Development of High Reliability Auxiliary Power Supply System

https://doi.org/10.5370/KIEE.2020.69.10.1561

김재원(Jaewon Kim) ; 김길동(Gildong Kim) ; 신승권(Seungkwon Shin) ; 조규정(Gyu-Jung Cho) ; 이한상(Hansang Lee)

For important railway equipment related to safety, efficient management and maintenance are required based on reliability, and for this, information on the life expectancy of the developed electronic equipment is required. Accordingly, in this paper, we deal with the reliability evaluation process to secure high reliability and obtain life expectancy information in the process of developing new APS(Auxiliary Power Supply) system that are 100 % compatible with existing APS system. The proposed reliability evaluation process was applied to the APS system under development by raising the reliability target of about 8 % compared to the existing one. Particularly, the vulnerable component can secure high reliability from the design stage through the reliability prediction and reliability demonstration based on accelerated life test. In the case of system reliability demonstration, the auxiliary power supply system equipped with improved vulnerable components that satisfy the reliability target of vulnerable components is installed on a railway vehicle, and the actual railway vehicle verification test is performed in an actual operating environment. The reliability evaluation process in this paper can be used as a way to secure high reliability in railway systems with many restrictions such as cost and test environment.

트램의 자율주행을 위한 동적 속도 프로파일 생성방법 A Dynamic Velocity Profile Generation Method for Autonomous Driving of a Tram Vehicle

https://doi.org/10.5370/KIEE.2020.69.10.1569

박성원(Sung-Won Park) ; 최경준(Kyung-Joon Choi) ; 황현철(Hyeon-Chyeol Hwang) ; 곽재호(Jae-Ho Kwak)

In this paper, a dynamic velocity profile generation method is proposed to meet the real time operation planning requirement of autonomous tram. This method takes into account the acceleration and jerk limit of a target vehicle to establish the reference profile with suitably chosen control modes. The modes are determined by the maximum braking distance estimation and velocity limit criteria of the routes such that a violation free profile is achieved, while related decision logic and parameters are derived analytically to make sure efficient computational cost. Based on the mode and states of profile, the usable values of acceleration and jerk are derived at each sample step, which facilitates the profile generation and correction in real time. The feasibility of the proposed approach is evaluated by simulation studies on a test scenario.