• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.194-196
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• 2001

This paper presents a hybrid algorithm for solving security constrained OPF in interconnected power systems, which is based on the combined application of evolutionary programming (EP) and sequential quadratic programming (SQP). The objective functions are the minimization of generation fuel costs and system power losses. In OPF considering security, the outages are selected by contingency ranking method. The control variables are the active power of the generating units, the voltage magnitude of the generator, transformer tap settings and SVC setting. The state variables are the bus voltage magnitude, the reactive power of the generating unit, line flows and the tie line flow. The method proposed is applied to the modified IEEE 14buses model system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.2006-2010
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• 2008

This paper deal with the improvement performance and test result of traction motor for Bimodal low floor vehicles that are CNG(Compressed Natural Gas) hybrid bus. The improvement performance concept of the traction motor is studied in terms of electrical characteristics and mechanical construction. Finally, this paper introduces the result of the traction motor test for low floor vehicles, and mentioned the detail design concept of traction motor.

• 대한전기학회논문지:전력기술부문A
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• 제49권2호
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• pp.43-49
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• 2000

It is a complex process to analyze power system voltage stability problems with all of the dynamics of a system, because a large power network system sophisticatedly consists of generators, lines, loads and so forth. So we considered the dynamics of loads so as to analyze voltage stability method- by carrying out an analysis of steady state voltage stability and dynamic voltage stability simultaneously. To perform a steady state voltage stability program in advance makes it possible to cut down on laborious calculations so that an analysis of dynamic voltage stability becomes concise. The validity and efficiency of the method presented in this paper were verified by applying the IEEE 14 bus system.

• 대한기계학회논문집B
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• 제35권2호
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• pp.189-196
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• 2011

최근, 승용차는 물론 대형차에서도 하이브리드시스템 등의 전기동력방식을 도입하려는 연구개발이 활발하다. 기존의 내연기관을 대체하는 전기구동모터를 이용하여 차량을 구동하는 전기동력방식을 채용하는 것이 한층 더 효율적이며 가속성능, 승차감 등의 면에서도 유리한 점이 많다. 그러나 모터는 엔진과 전혀 다른 특징을 갖기 때문에 동력성능과 에너지효율에 관한 적합한 평가수법을 검토할 필요가 있다. 본 논문에서는 전기구동버스에 대한 구동모터 시스템을 다이나모미터 상에서 운전하여, 노선버스의 운행패턴을 반영한 모의운전을 실시, 가속성능 및 에너지변환효율, 회생효과의 평가방법 등을 고찰하였다. 그 결과 실 주행 패턴운전에 대한 모터일률, 전력량 등의 계측으로부터 모터 변환효율은 90% 전후, 회생전력량은 요구전력량의 40% 이상으로 평가되었다.

• 한국수소및신에너지학회논문집
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• 제34권2호
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• pp.91-99
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• 2023

Participation in power trading using surplus power is considered a business model active in the domestic energy trade market, but it is limited only if the legal requirements according to the type, capacity, and use of the facilities to be applied for are satisfied. The hydrogen residential demonstration model presented in this paper includes solar power, energy storage system (ESS), fuel cell, and water electrolysis facilities in electrical facilities for private use with low-voltage power receiving system. The concept of operations strategy for this model focuses on securing the energy self-sufficiency ratio of the entire system, securing economic feasibility through the optimal operation module installed in the energy management system (EMS), and securing the stability of the internal power balancing issue during the stand-alone mode. An electric facility configuration method of a hydrogen residential complex demonstrated to achieve this operational goal has a structure in which individual energy sources are electrically connected to the main bus, and ESS is also directly connected to the main bus instead of a renewable connection type to perform charging/discharging operation for energy balancing management in the complex. If surplus power exists after scheduling, participation in power trading through reverse transmission parallel operation can be considered to solve the energy balancing problem and ensure profitability. Consequentially, this paper reviews the legal regulations on participation in electric power trading using surplus power from hydrogen residential models that can produce and consume power, gas, and thermal energy including hybrid distributed power sources, and suggests action plans.

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.161-172
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• 2017

In the paper, a hybrid technique is proposed for detecting the location and capacity of distributed generation (DG) sources like wind and photovoltaic (PV) in power system. The novelty of the proposed method is the combined performance of both the Biography Based Optimization (BBO) and Particle Swarm Optimization (PSO) techniques. The mentioned techniques are the optimization techniques, which are used for optimizing the optimum location and capacity of the DG sources for radial distribution network. Initially, the Artificial Neural Network (ANN) is applied to obtain the available capacity of DG sources like wind and PV for 24 hours. The BBO algorithm requires radial distribution network voltage, real and power loss for determining the optimum location and capacity of the DG. Here, the BBO input parameters are classified into sub parameters and allowed as the PSO algorithm optimization process. The PSO synthesis the problem and develops the sub solution with the help of sub parameters. The BBO migration and mutation process is applied for the sub solution of PSO for identifying the optimum location and capacity of DG. For the analysis of the proposed method, the test case is considered. The IEEE standard bench mark 33 bus system is utilized for analyzing the effectiveness of the proposed method. Then the proposed technique is implemented in the MATLAB/simulink platform and the effectiveness is analyzed by comparing it with the BBO and PSO techniques. The comparison results demonstrate the superiority of the proposed approach and confirm its potential to solve the problem.

• 한국인터넷방송통신학회논문지
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• 제19권6호
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• pp.191-196
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• 2019

도시철도 시설물의 경우, 대중교통의 특성상 전력공급이 차단되면 혼란이 발생하므로 통신설비, 방재설비 및 승차장 안전문 등이 안전한 승객의 이동을 위해 전원공급이 유지되어야 한다. 또한, 도시철도 운행노선에는 다수의 전동차가 운행 중이므로 운행 간격과 시설복구 시간을 고려하면 승차장 안전문은 최소 30분 이상, 통신설비 및 방재설비는 1시간 이상의 설비가동이 요구된다. 따라서 도시철도 구간의 역사나 차량화재발생 시 화재로 인한 추가확산을 막기 위해 주요전력이 차단되므로 유도등 및 배연설비의 안정적 동작 유지를 위해 비상 전원공급이 필수적이다. 최근에는 비상시 정전을 방지하는 UPS (uninterruptible power supply, 무정전 전원공급장치) 기능과 가격이 저렴한 야간 시간대에 전기를 저장하였다가 주간 피크시간대에 사용할 수 있도록 하여 전기요금을 절감해주는 ESS 기능을 합친 비상발전용 UPS 기능을 갖춘 복합형 전력저장시스템을 개발하는 추세이다.

• Journal of Electrical Engineering and Technology
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• 제12권5호
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• pp.1729-1742
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• 2017

In designing System Protection Schemes (SPSs) in power systems, protecting transmission network against extreme undesired conditions becomes a significant challenge in mitigating the transmission line overloading. This paper presents an intelligent Special Protection and Control Scheme (SPCS) using of Differential Evolution with Adaptive Mutation (DEAM) approach to obtain the optimum generation rescheduling to solve the transmission line overloading problem in system contingency conditions. DEAM algorithm employs the attraction-repulsion idea that is applied in the electromagnetism-like algorithm to support the mutation process of the conventional Differential Evolution (DE) algorithm. Different N-1 contingency conditions under base and increase load demand are considered in this paper. Simulation results have been compared with those acquired from Genetic Algorithm (GA) application. Minimum severity index has been considered as the objective function. The final results show that the presented DEAM method offers better performance than GA in terms of faster convergence and less generation fuel cost. IEEE 30-bus test system has been used to prove the effectiveness and robustness of the proposed algorithm.

• Journal of Power Electronics
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• 제11권4호
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• pp.479-489
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• 2011

The bidirectional dc-dc converter, being the interface between Energy Storage Element (ESE) and DC bus, is an essential component of the power management system for vehicle applications including electric vehicle (EV), hybrid electric vehicle (HEV), and fuel cell vehicle (FCV). In this paper, a novel multiphase bidirectional dc-dc converter interfacing with battery to supply and absorb the electric energy in the FCV system was studied with the help of real time digital simulator (RTDS). The mathematical models of fuel cell, battery and dc-dc converter were derived. A power management strategy was developed and first simulated in RTDS. A Power Hardware-In-the-Loop (PHIL) simulation using RTDS is then presented. The main challenge of this PHIL is the requirement for a highly dynamic bidirectional Simulation-Stimulation (Sim-Stim) interface. This paper describes three different interface algorithms. The closed-loop stability of the resulting PHIL system is analyzed in terms of time delay and sampling rate. A prototype bidirectional Sim-Stim interface is designed to implement the PHIL simulation.

• 전기학회논문지
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• 제58권9호
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• pp.1658-1666
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• 2009

This paper proposes an approach of Mult_HPSO based on the PC cluster system to reduce or remove the stagnation on an early convergence effect of PSO, reduce an execution time and improve a search ability on an optimal solution. Hybrid PSO(HPSO) is combines the PSO(Particle Swarm Optimization) with the mutation of conventional GA(Genetic Algorithm). The conventional PSO has operated a search process in a single swarm. However, Multi_PSO operates a search process through multiple swarms, which increments diversity of expected solutions and reduces the execution time. Multiple Swarms are composed of unsynchronized PC clusters. We apply to SCED(security constrained economic dispatch) problem, a nonlinear optimization problem, which considers line flow constraints and N-1 line contingency constraints. To consider N-1 line contingency in power system, we have chosen critical line contingency through a process of Screening and Selection based on PI(performace Index). We have applied to IEEE 118 bus system for verifying a usefulness of the proposed approaches.