• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1059-1065
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• 2011

In line with the expansion of electric railway, reducing carbon emission and optimal train operation are required by economical, eco-friendly and efficient management. Most of the energy consumption in electric railway is consumed by train operation. So it is important that minimize the energy consumption in train operation. An analysis of the operation performance of the new model vehicle which in South Korea, Korail introduced shows that the energy consumption is different in line with the skill level of the engine driver. In this study, the know-how of train operation of a skilled engine driver is systematized by using artificial intelligence, and the technique which supports engine drivers with train operation was offered. As a result of applying in South Korea, the Gyeongbu line by using simulation, it confirmed that the maximum 20% can reduce the energy consumption in comparison with unskilled engine drivers in case of applying the Expert System.

• Journal of Electrical Engineering and Technology
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• 제8권4호
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• pp.712-718
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• 2013

With the development of industry and the improvement of living standards, better quality in power electric service is required more than ever before. This paper deals with the optimal algorithms for voltage regulation in the case where Distributed Storage and Generation (DSG) systems are operated in distribution systems. It is very difficult to handle the interconnection issues for proper voltage managements, because the randomness of the load variations and the irregular operation of DSG should be considered. This paper proposes the optimal on-line real time voltage regulation methods in power distribution systems interconnected with the DSG systems. In order to deliver suitable voltage to as many customers as possible, the optimal sending voltage should be decided by the effective voltage regulation method by using artificial neural networks to consider the rapid load variation and random operation characteristics of DSG systems. The simulation results from a case study show that the proposed method can be a practical tool for the voltage regulation in distribution systems including many DSG systems.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 춘계학술대회 논문집
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• pp.135-141
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• 2002

Recently, in the metro railways, researches on the skip-stop operation and development of the double deck train-set are active, which is to improve the service quality through reducing the passenger travel time and suppling seating service. Constructing new line or reforming the existent line needs huge amount of budget. Therefore, previous to start these large scale projects, scrutiny on benefit improvement, cost reduction and those optimal trade-off is indispensable. In this paper, a quantitative analysis to determine the optimal train service patterns and train-sets necessary is proposed, under the skip-stop operation condition in the metro railways. The analysis models are formulated in mathematical programming model, and tested validity using the LINGO 7.0.

• 전기학회논문지
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• 제60권8호
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• pp.1467-1472
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• 2011

This paper presents an optimal operation of microgrid systems and considering a tie-lines capacities that concerned each grid. The microgrid system consists of a wind turbine, a diesel generator, and a fuel cell. An one day load profile and wind resource for wind turbine generator were used for the study. For the grid interconnection, tie-line capacities were applied as constraints. The capacity constraints of tie-lines in production cost analysis are very important issues in the operation and planning of microgrid. In optimization, the Harmony Search (HS) algorithm is used for solving the problem of microgrid system operation which a various generation resources are available to meet the customer load demand with minimum operating cost. The application of HS algorithm to optimal operation of microgrid proves its effectiveness to determine optimally the generating resources without any differences of load mismatch.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.360-362
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• 2003

In operation of distribution system, DGs(Distributed Generations) are installed as an alternative of extension and establishment of substations, transmission and distribution lines according to increasing power demand. Optimal capacity and allocation of DGs improve power quality and reliability. This paper proposes a method for determining the optimal number, size and allocation of DGs needed to minimize operation cost of distribution system. Capacity of DGs for economic operation of distribution system can be estimated by the load growth and line capacity during operation planning duration. DG allocations are determined to minimize total cost with failure rate and annual reliability cost of each load point using GA(Genetic Algorithm).

• 전기학회논문지
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• 제56권3호
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• pp.451-456
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• 2007

This paper presents a problem that reconfigure distribution power system using branch exchange method. Optimal reconfiguration problem calculates line loss, voltage condition about system states of all situations that become different according to line On/off status, and search for optimum composition of these. However, result is difficult to be calculated fast. Because radiated operation condition of system is satisfied using many connection and sectionalize switches in the distribution power system. Therefore, in this paper, optimization method for reducing system total loss and satisfying operating condition of radial and constraints condition of voltage is proposed using the fastest branch exchange. And optimal solution at branch exchange algorithm can be wrong estimated to local optimal solution according to initial operating state. Considering this particular, an initial operating point algorithm is added and this paper showed that optimal solution arrives at global optimal solution.

• 대한전기학회논문지:전력기술부문A
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• 제51권3호
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• pp.118-126
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• 2002

AVR parameter tuning for voltage control of generators has generally been done with the off-line open-circuit model of the synchronous generator. When the generator is connected on-line and operating with load the AVR operates in an entirely different environment from the open-circuit conditions. This paper describes a new method for AVR parameter tuning for on line conditions using SQP(Sequential Quadratic Programming) meshed with frequency response characteristics of linearized on-line system model. As the proposed method uses the un - line system model the tuned parameter sets show more optimal behavior in the on-line operating conditions. furthermore, as this method considers the performance indices that are needed for stable operation as constraints, AVR parameter sets that are tuned by this method could guarantee the stable performance, too.

• KIEE International Transactions on Power Engineering
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• 제4A권1호
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• pp.42-47
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• 2004

This paper presents the various application programs for the Distribution Automation System (DAS) of the Korea Electric Power Corporation (KEPCO)'s distribution system. These programs are developed to allow for optimal operation in the areas of feeder automation, relay coordination, loss minimization and so on. They are single line diagram auto creation programs for the feeder, service restoration program, protection coordination program, data error detection program, and optimal network reconfiguration program. The details of these programs are presented for validity and effectiveness.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.1238-1240
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• 1998

For economic operating of distribution system, utility has to minimize the loss in distribution line by controlling reactive power and power factor. This paper presents calculation of reactive power in distribution line, estimation of the condenser capacity according to distance, and computation of optimal location and proper condenser capacity.

• 조명전기설비학회논문지
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• 제12권2호
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• pp.69-76
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• 1998

본 논문에서는 배압터빈과 추기복수터빈으로 이루어진 열병합 발전플랜트의 최전운전을 결정할 수 있는 새로운 알고리즘을 제시한다. 제시한 알고리즘은 플랜트가 운전중에 직접 온 라인으로 취할 수 있는 증가량만을 파라메타로 하여 보일러와 터빈-발전기의 최적부하를 결정할 수 있다. 본 알고리즘은 비선형 경비함수와 해당 제한사항들로 이루어져 있으며 실제 운전중인 열병합 발전플랜트와 비교 시뮬레이션을 실시한 결과 만족할만한 결과를 얻었다. 즉 실제 운전 데이터와 비교해본 결과 공정의 증기 부하량에 따라 1.2∼4.5[%]의 운전경비 절감효과를 얻을 수 있었다. 또한 본 알고리즘은 필요한 입력 데이터를 공정으로부터 쉽게 온 라인으로 취할 수 있어 프로세스 컴퓨터로 용이하게 구현할 수 있다.