• 대한전기학회
Mobile QR Code QR CODE : The Transactions of the Korean Institute of Electrical Engineers
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가상 발전소 운영에 따른 배전망 영향 분석을 위한 집합 모델 개발 Development of Aggregation Models to Analyze the Impact of Virtual Power Plant Operation on the Distribution Network

https://doi.org/10.5370/KIEE.2024.73.6.931

현석우(Seok-Woo Hyun) ; 최윤혁(Yun-Hyuk Choi)

Accelerating worldwide energy transition trends and the continuous proliferation of renewable energy facilities have exacerbated energy volatility and compromised system stability. Accordingly, this paper proposes an aggregation model for selecting resources to output by integrating generation-type resources and demand-type resources, and grouping resources according to sensitivity. Implemented using the OpenDSS-Matlab interconnection system, the accuracy of the model was validated through an analysis of its effects on distribution system voltage stability.

체감온도와 도일 변수 도입을 통한 편의점 전력 사용량 예측개선에 관한 연구 A Study on Improving Convenience Store Power Consumption Prediction Through the Introduction of Apparent Temperature and Degree Day Variables

https://doi.org/10.5370/KIEE.2024.73.6.939

김기한(Ki-Han Kim) ; 김정욱(Jeong-Uk Kim)

Accurate prediction is crucial for establishing energy management strategies. This study proposes a method to enhance the accuracy of predicting power consumption in convenience stores by considering the necessity of heating and cooling. We collected building energy usage data and meteorological data from 86 convenience stores nationwide, incorporating perceived temperature and daily variables into machine learning models. Case studies before and after introducing these variables were conducted to evaluate the model's performance, confirming notably improved accuracy, especially with CatBoost and Stacking models. Through this approach, maximizing energy management efficiency and optimizing energy consumption can be achieved in existing buildings without additional equipment installation.

고장파급방지장치의 미탈락발전기 발전제약 완화를 위한 전기저장장치 효과 분석 및 운영방안 Effect Analysis and Operation Method of the ESS for Relieving Power Generation Constraints of Non-Tripping Generators in SPS

https://doi.org/10.5370/KIEE.2024.73.6.946

김영찬(Young-Chan Kim) ; 송유훈(Yu-Hoon Song) ; 이태승(Tae-Seung Lee) ; 임지훈(Ji-Hoon Lim) ; 오상현(Sang-Hyun Oh) ; 국경수(Kyung-Soo Kook)

This study introduces an effect analysis and operation method of Energy Storage Systems(ESS) to relieve the power generation constraints of SPS non-tripping generators. The power generation constraints of non-tripping generators have been applied as a part of the Special Protection Scheme(SPS), which is operated to maintain the transient stability even in the event of transmission line failures connecting large power plants. We propose the application of ESS as a frequency control resource to mitigate the power constraints on non-tripping generators by enabling a reliable increase in the number of SPS tripped generators, thus enhancing transient stability. In the proposed method, the effect of ESS is quantified by dividing the released amount of the generation constraints of non-tripping generators by the applied amount of ESS. Also, the combinations of the number of SPS trip generators and their corresponding power generation constraints of non-tripping generators are proposed as the operation method of SPS with ESS. The effectiveness of the proposed method is verified through study cases employing Korean power system developed for the basic plan of long-term electricity supply and demand.

복합소호 가스 차단기의 다중 아킹 타임 차단 성능 확보를 위한 설계 최적화 Design Optimization to Secure Multiple Arcing Time Interruption Performance of Self-Blast Gas Circuit Breakers

https://doi.org/10.5370/KIEE.2024.73.6.955

곽창섭(Chang-Seob Kwak) ; 백명기(Myung-Ki Baek) ; 강성모(Sung-Mo Kang) ; 이상화(Sang-Hwa Lee) ; 김성주(Sung-Ju Kim)

Recently, the focus has been on the development of self-blast gas circuit breakers with low operating force and compact design. The self-blast gas circuit breaker uses the high-temperature energy from the arc to nozzle ablation and increase the pressure in the heating chamber. In order to predict the interruption performance of a developed product, heat gas flow analysis is essential and must be accompanied by judgment criteria according to test type. In this paper, based on short line fault (SLF) test data of a 170kV 50kA 60Hz self-blast gas circuit breaker, the interrption performance index for each arcing time is derived and the critical point is secured. The index is calculated based on the pressure rise and heat gas emissions that are important for interrpution performance, and a design plan that satisfies interrpution performance at all arcing times is presented step by step. Depending on the process, a design that can satisfy interrpution performance at all arcing times is derived. Reliability is secured by comparing the analysis results and blocking performance indices of the proposed candidates and the reference model and verifying them through testing.

직류차단기 고속스위치를 위한 영구자석식 접점 고정시스템 설계 및 해석 Design and Analysis of a Magnetic Holding System of Electrical Contact for Fast Switches of DC Circuit Breakers

https://doi.org/10.5370/KIEE.2024.73.6.961

심민섭(Min-Seob Sim) ; 이희준(Hee-Jun Lee) ; 백명기(Myung-Ki Baek)

This paper introduces the Spoke-type permanent magnet force holding unit for the DC circuit breaker's fast switch. The permanent magnet force holding unit of a fast switch is a device for applying a contact force to the contact interface of the vacuum interrupter in the close state of the circuit breaker. However, not a few contact forces remaining during the open operation interfere with the actuator operation and slow down the operation speed of the fast switch. To solve this problem, in this paper, a Spoke-type permanent magnet force holding unit that can improve operation inhibition through a downward slope of the contact force was proposed, designed and interpreted. The effectiveness and performance of the proposed model were verified by comparing with the analysis results of the conventional model.

간단한 수학적 기법을 이용한 얇은 도체로 이루어진 2차원 도체망 주위의 정전위 분석 Electrostatic Potential Analysis Around Two Dimensional Thin Crossed Conducting Meshes Using Simple Mathematical Methods

https://doi.org/10.5370/KIEE.2024.73.6.968

한인수(In-Su Han)

It is In general, the conducting meshes are used to shield electric field and to make the potential around them nearly constant. Because of their lots of availability, the conducting meshes are used prevalently in the diverse industry(ex. nuclear engineering, high-voltage engineering, and etc.). In this paper, we derive the analytical voltage related equation about the repetitive periodic conductors using Laplace equation. At first, we derive the mathematical equation about the repetitive periodic conductors and expand this equation into two dimensional thin crossed conducting meshes by Laplace equation and delta function. Finally, we compare the induced results with the commercial numerical analysis program based results and express the validity of the analytical methods.

대역저지 특성개선을 위해 LTCC기술을 적용한 광대역 인터디지털 대역통과필터 설계 Design of Broadband Interdigital BPF Using Low-Temperature Co-Fired Ceramic(LTCC) Technology for The Improvement of Bandstop Range

https://doi.org/10.5370/KIEE.2024.73.6.973

김소희(Sohui Kim) ; 박경민(Kyungmin Park) ; 안달(Dal Ahn) ; 장유나(Youna Jang)

This paper proposes a 7th order interdigital band-pass filter using LTCC technology to achieve miniaturization and S-band pass characteristics. To eliminate harmonics, the proposed structure includes vias placed at 1mm intervals around the edges, which not only suppress harmonic components but also improve frequency selectivity. The proposed filter implements a broadband filter with a center frequency of 3GHz and a bandwidth of 2GHz. The implemented filter has an insertion loss of -0.79dB and a return loss of -29.42dB in the specified frequency band, and it is miniaturized to a size of ×× ??  .

Bi 용액-용융으로부터 얻은 nGaAs-n+(GaAs)1-x-y(Ge2)x(ZnSe)y 이종구조의 스펙트럼 감광성 조사 Investigation of the Spectral Photosensitivity of nGaAs-n+(GaAs)1-x-y(Ge2)x(ZnSe)y Heterostructure Obtained from Bi Solution-Melt

https://doi.org/10.5370/KIEE.2024.73.6.980

(Ismailov Shavkat Kuzievich) ; (Saidov Amin Safarbaevich) ; (Usmonov Shukrullo Negmatovich) ; (Saparov Dadajan Valixanovich) ; (Eshonkhojaev Dilmurod Odilovich) ; (Asatova Umida Palvanovna) ; (Bobojanov Sukhrob Gayratovich)

This paper presents the possibility of the formation of a (GaAs)1-y-x( Ge2)y(ZnSe)х solid solution based on chemical elements of groups II, III, IV, V and VI depending on the charge state and covalent radii of the molecules of the solution-forming components. This paper presents the results of experimental studies of the spectral photosensitivity of the n-GaAs?n+ (GaAs)1-x-y (Ge2)x(ZnSe)y heterostructure and atomic force microscopy of the surface of an epitaxial film of a molecular substitution solid solution (GaAs)1-y-x( Ge2)y(ZnSe)х grown from Bi solution-melt on GaAs substrates. The photosensitivity of n-GaAs?n+ (GaAs)1-x-y(Ge2)x(ZnSe)y heterostructures covers the photon energy range from 1.3 eV to 2.5 eV, with maxima at 1.6 eV, 2.0 eV, and 2.4 eV. On the surface of the (GaAs)1-y-x( Ge2)y(ZnSe)х epitaxial film, nanocrystallites with a height c ~ 6.5?7.5 nm and a base width ~ 120?150 nm were found. The concentration of nanocrystals on the surface of the epitaxial film was ~ 2.5?108 sm-2.

배전용 케이블 통계수명 평가 및 초기고장 제거의 적정성 검토 Statistical Life Expectancy Evaluation of MV Cables and Adequacy Review of Early Failure Removal

https://doi.org/10.5370/KIEE.2024.73.6.987

조종은(Chongeun Cho) ; 이온유(Onyou Lee) ; 박병석(Byungseok Park)

In this paper, the change history of various types of MV(Medium Voltage) cables was investigated. In addition, the statistical life expectancy of each type was calculated by using the operation data and the failure data. As a result of reviewing the adequacy of eliminating early failure, cut-off year is 10 years. Realistically applicable statistical life expectancy is calculated by correcting the cause of failure entered by mistake. The life expectancy of CNCV cable is calculated as 31.4 years, CNCV-W 38.1 years, FR CNCO-W 51.2 years and the overall average is 33.8 years. Currently, the life expectancy of TR CNCV-W is 29.4 years, but it is estimated that the lifespan will be extended if failure data is accumulated. As a result, it is expected that life expectancy results can be applied to Asset Management System (AMS) in the future.

메카트로닉 모듈의 기능적 선형 작동 요소의 그룹 제어 Group Control of Functional Linear Actuation Elements of Mechatronic Modules

https://doi.org/10.5370/KIEE.2024.73.6.995

(Matyokubov Nurbek Rustamovich) ; (Rakhimov Temurbek Omonboevich) ; (Bobojanov Sukhrob Gayratovich)

Robots and robotic complexes are widely used in modern production processes. Their performance and principles are mainly related to the mechatronic modules based on their performance elements. The organization of the control process of an industrial robot allows to consider the discrete nature of technological operations and the characteristics of functional linear actuation elements of interacting mechatronic modules, in general, the logical level of group control, as a discrete control object. The article is focused on the structural scheme of the mechatronic module control and the movement cyclogram of the functional linear actuators in accordance with the mobility level and positions of the industrial robot, which serves to express the sequence of linear and angular reversible step movements simultaneously in space coordinates. Taking into account the positions and mobility levels of the industrial robot manipulator in the group control of the functional linear actuators of the mechatronic modules, a method of obtaining a sequence of control commands and a group logic control algorithm has been developed based on the cyclogram depending on the spatial coordinate systems. Based on the group logical control algorithm, the functional model of the electromagnetic-mechanical properties of the functional linear mechatronic modules actuators and their structural structure are presented.

정제된 특징 공간에서의 윈도우 어텐션이 적용된 Vision Transformer기반 이미지 분류 성능 개선 연구 Refined Feature-Space Window Attention Vision Transformer for Image Classification

https://doi.org/10.5370/KIEE.2024.73.6.1004

유다연(Dayeon Yoo) ; 유진우(Jinwoo Yoo)

The window-based self-attention vision transformer (ViT) reduces computational complexity by computing attention within a specific window. However, it is difficult to capture the interactions between pixels from different windows. To address this issue, Swin transformer, a representative window-based self-attention ViT, introduces shifted window multi-head self-attention (SW-MSA) to capture the cross-window information. However, tokens that are distant from each other still cannot be grouped into one window. This paper proposes a method to cluster tokens based on similarity in the feature-space and compute attention within the cluster. The proposed method is an alternative to the SW-MSA of the existing Swin transformer. Additionally, this paper adopts a method to refine the feature space using convolutional block attention module (CBAM) to enhance the representational power of the model. In experimental results, the proposed network outperforms existing convolutional neural networks and transformer-based backbones in the classification task for ImageNet-1K.

항법성능을 고려한 수중 자율이동체의 축소차수 동특성모델 결정방법 Reduced-Order Underwater Vehicle Dynamics Model Determination Considering Navigation Performance

https://doi.org/10.5370/KIEE.2024.73.6.1012

김진관(Jin-Kwan Kim) ; 황익호(Ick-Ho Whang) ; 나원상(Won-Sang Ra) ; 박승효(Seung-Hyo Park)

This paper proposes a novel approach to VDM(vehicle dynamics model) determination problem for model-aided navigation of an AUV(autonomous underwater vehicle) when the DVL(doppler velocity log) is unavailable. The conventional algorithms have been developed based on the well-known GHM(Gertler-Hagen hydrodynamics model). Unfortunately, the GHM is generally high-ordered so that it is hard to design GHM based applications working stable in actual situations with high uncertainties. To improve this problem, idea to use the transfer function for ground-heading control loop instead of GHM was proposed but it is still high-ordered to retain the stability problems. In this paper, we suggest a revolutionary reduced order VDM for AUV model-aided navigation. The order of our model is drastically reduced enough to show stable and consistent performances in real applications, while the errors due to the model reduction are mitigated under the newly introduced concept of zero model-output error integral to produce small dead-reckoning navigation errors. Simulation results show that our method demonstrates critically improved performances, compared to conventional EKF(extended Kalman filter) methods using the closed-loop heading control transfer function, in stability and consistency

Magnetic Coupling을 이용한 차륜검지센서의 특성 분석 Characteristic Analysis of Wheel Detection Sensor Using Magnetic Coupling

https://doi.org/10.5370/KIEE.2024.73.6.1023

박현수(Hyunsoo Park) ; 이종우(Jongwoo Lee)

The use of eddy current is widely used in industrial applications such as non-destructive testing and automation devices and has become commonplace. In this paper, we verified that the effect of Eddy Current on the detection distance of the wheel is related to the distance through the magnetic circuit modeling of the single-sided sensor for the axle counter using the Eddy Current sensor principle, and confirmed that the impedance changes due to the change of the inductance and resistance value depending on the distance, and this phenomenon causes the sensor coil voltage amplitude to change. Therefore, through theoretical analysis and experiments, we verified that the impedance change and magnetic field change caused by the Eddy Current through the magnetic circuit modeling and experiments are factors that affect the detection distance.

중성점 접지방식 단권변압기 급전계통 고장점 표정 기술향상에 관한 연구 A Study on the Improvement of Fault Locator Technology for Neutral Point Grounding Auto Transformer Power Feeding System

https://doi.org/10.5370/KIEE.2024.73.6.1031

권정근(Jeong-Keun Kwon) ; 이종우(Jong-Woo Lee)

In the event of a power feeding system failure, the railway operator institution must quickly identify and respond to the cause of the power feeding system failure and to recover from the failure. If the failure location of the power feeding system is not accurately identified, the power supply failure is repeated, and the train operation in the section is impossible. Therefore, a separate device is needed to accurately identify the failure section, and this device can quickly recover by indicating the failure location. However, when an actual failure occurs, the accuracy of the positional expression of the currently operating automatic failure position display device (hereinafter referred to as a fault point expression device) caused confusion in recovery. Therefore, in this study, we intend to review improvement measures for short circuit impedance measurement, failure current measurement, and failure location indication that can reduce errors in high-fault expression devices.

역설계를 활용한 전기철도 부품의 표준도면 도출 : 전차선로 현수클램프 사례 연구 Reverse Engineering for Accurate Standard Drawings of Electric Railway Components: A Case Study with Catenary Clamps

https://doi.org/10.5370/KIEE.2024.73.6.1038

성동일(Dong-IL Sung) ; 이종우(Jongwoo Lee) ; 오완식(Wan-Shik Oh) ; 이훈서(Hunseo Lee) ; 박영(Young Park)

Accurate design drawings are crucial for the safe and efficient operation of railway systems. However, inconsistencies, errors, and missing dimensions in existing drawings can hinder the manufacturing of identical parts. To address this challenge, this paper proposes a reverse engineering (RE) process to extract standard drawings of electric railway system components based on the Korea Rail Standard Authority (KRSA) specifications. We demonstrate the effectiveness of the proposed RE process by applying it to a high-speed railway catenary clamp. The 3D scanning data was accurately processed, resulting in a high-precision CAD model with an error margin of ±0.8 mm. The generated 2D drawing includes all the necessary details for manufacturing, assembly, and inspection. The results show that the proposed RE process can effectively extract standard drawings of electric railway system components from 3D scanning data. These generated 2D drawings can be used for various purposes, such as manufacturing, maintenance, and BIM (Building Information Modeling) model creation.

풀브릿지 다이오드 클램프 4레벨 비대칭 스위칭 컨버터 Full-Bridge Diode-Clamped Four-Level Asymmetric Switching Converter

https://doi.org/10.5370/KIEE.2024.73.6.1042

송민섭(Min-Sup Song) ; 김재원(Jaewon Kim) ; 정호성(Hosung Jung) ; 김형철(Hyungchul Kim)

In this paper, a full-bridge diode-clamped four-level asymmetric switching converter with pulse-amplitude-modulation (PAM) was proposed. Since the proposed converter is implemented using a multi-neighboring reference vector discontinuous PWM (MNRV DPWM) based on the symmetric two half-bridge (HB) control, the implementation of the MNRV DPWM algorithm is very easy. The steady-state operating characteristics of the proposed converter, including voltage gain, were analyzed. The voltage deviation of the DC link capacitors was eliminated and the output voltage was controlled by the PAM in a simple linear manner. The proposed converter has the advantage of reducing reactive power compared to the existing phase-shift method by an additional powering cycle. The effectiveness of the proposed converter was verified through simulation.

LVDC 배전망의 실증 운영에 대한 고찰 A Study on Empirical Operation of Low-Voltage Distribution Network

https://doi.org/10.5370/KIEE.2024.73.6.1053

고병선(Byoung-Sun Ko) ; 차대석(Dae-Seak Cha) ; 채상헌(Sang-Heon Chae) ; 최정식(Jung-Sik Choi)

This article represents the LVDC demonstration site consisting of LVDC distribution networks, DC consumer, and an AC-DC connected consumers, establishes a demonstration scenario, and presents the results of empirical data. A demonstration scenario is established for the purpose of confirming the stable coordinated operation and protective functions of components at the demonstration site. Each scenario is implemented at the LVDC demonstration site. The LVDC distribution network can be regarded as a noise collector of power electronic converters, the impact of this on the system operation is analyzed.

LVDC 마이크로그리드 환경에서 효율적인 ESS 충방전 운영 알고리즘 연구 A Study on the Efficient ESS Charging/Discharging Operation Algorithm in LVDC Microgrid Environment

https://doi.org/10.5370/KIEE.2024.73.6.1063

정상우(Sang-Woo Jung) ; 안윤영(Yoon-Young An) ; 김기일(Ki-Il Kim)

Modern power systems are developing in a sustainable and energy-efficient direction, and research on intelligent power grids that accommodate new and renewable energy is being actively conducted. Since new and renewable energy-based distributed power generation systems and ESS are output as DC power, the DC microgrid reduces the power conversion step and improves the stability and efficienc of the power distribution network. The core of this study is to compare and analyze the performance of the three charge/discharge operation algorithms based on AI prediction in the LVDC microgrid environment. The AI server learns real-time data through interworking with the EMS to predict future load usage and solar power generation, and performs the charge/discharge operation algorithm of ESS based on the collected ESS state data. This paper presents the configuration of the LVDC microgrid testbed, the integration method between EMS and electrical facilities, and analyzes the performance of the developed ESS charge/discharge operation algorithm. It also evaluates the effectiveness of each operation algorithm through actual operation data and simulation, analyzes how these strategies contribute to system load reduction and energy efficiency improvement, and provides guidelines for selecting the optimal ESS charge/discharge operation algorithm under specific conditions.

비절연형 SMPS로 구동되는 LED 경관조명등의 누전감지 회로에 관한 연구 A Study on the Earth Leakage Detection Circuit of LED Landscape Lighting Driven by Non-Isolated SMPS

https://doi.org/10.5370/KIEE.2024.73.6.1074

곽동걸(Dong-Kurl Kwak) ; 박근영(Keun-Young Park) ; 정회중(Hoe-Joong Jeong)

Recently, the LED industry is rapidly developing due to eco-friendly and energy saving. The government and each local government are actively equipped with LED lights to create urban landscapes such as crowded streets, parks, beaches, and roadsides under the paradigm of improving the urban environment. However, despite the splendor of LED landscape lighting, they are indifferent to safety accidents. In particular, LED landscape lighting has a lot of connecting lines between lighting lights and long wires, so there is a high risk of electrical leakage faults. These leakage faults have problems leading to power loss, power outages as well as human damage. Moreover, the non-isolated SMPS (Switch Mode Power Supply), which is used as AC-DC power conversion system for LED lights, is widely used for its small, light, and low-cost advantages, but a safety device for leakage fault is essential. This paper proposes a new circuit topology to prevent leakage faults by detecting leakage voltages using a ground resistance and a leakage point contact resistance rather than conventional leakage current detection methods to detect and prevent leakage faults such as LED lighting driven by non-isolated SMPS. In addition, each resistance component used, such as a ground resistance and a contact resistance, is composed of a Wheatstone bridge circuit and an instrumentation amplifier is used, giving the advantage of excellent reliability and responsiveness to detection of LED lighting leakage faults.

3상 전동기 제어반의 결상사고 감지를 위한 회로 토폴로지에 관한 연구 A Study on Circuit Topology for Open-Phase Fault Detection of 3-Phase Motor Control Panel

https://doi.org/10.5370/KIEE.2024.73.6.1080

곽동걸(Dong-Kurl Kwak) ; 최승민(Seung-Min Choi) ; 김대석(Dae-Suck Kim)

When a open-phase occurs in a 3-phase power system using a 3-phase motor, an unbalanced current applies to the power system, results in a fire due to overcurrent in the motor coil and great damage to the power system. The conventional open-phase detector of the 3-phase motor is mainly used with a THR (Thermal over-current Relay) or an EMPR (Electronic Motor Protection Relay). However, since these detector have the principle of detecting open-phase faults by sensing currents in 3-phase lines, it causes malfunction from the surge or external noise currents, and it is difficult to install the detectors. In order to solve these problems, this paper proposes a method and circuit topology for detecting the open-phase faults by detecting 3-phase voltages rather than detecting 3-phase currents. The proposed open-phase detection circuit is designed in a structure using the output voltage waveform and magnitude of the 3-phase half-wave rectification circuit. Since the proposed detector is designed with a voltage type, there are no malfunctions from the surge or external noise currents and the detector is simple and compact, giving ease of installation.

퍼지-계층화 분석법을 활용한 옥상형 풍력발전의 안전성 평가 Safety Assessment for Rooftop Wind Turbines Using Fuzzy-AHP

https://doi.org/10.5370/KIEE.2024.73.6.1087

신석현(Seok-Hyeon Shin?Sam-Chan Lee?In-Su Bae?Dong-Min Kim) ; 이샘찬() ; 배인수() ; 김동민()

Recently, wind power as a renewable energy resource has been widely used throughout the world, and the range of structure types, including small and rooftop wind turbines, has expanded. Consequently, the demand for small wind turbines on rooftops in residential areas is increasing, underscoring the importance of safety evaluations. However, there are no domestically certified rooftop small wind turbines, and reasonable safety assessments have not been conducted for the introduction of existing small wind turbines onto rooftops. Therefore, this paper proposes an index for the safety assessment of rooftop wind turbines and suggests a methodology for evaluating safety. The proposed index combines weights based on the Analytic Hierarchy Process(AHP) and Fuzzy logic to quantify qualitative factors. In the case study, the proposed safety index for rooftop wind turbines is assessed based on actual data obtained through a survey of approximately 150 experts, and its usefulness is validated. It is expected that the proposed safety assessment methodology will serve as a criterion for the installation and distribution of rooftop small wind turbines, ensuring their safe operation.