• 대한전기학회논문지:전력기술부문A
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• 제49권3호
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• pp.95-106
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• 2000

The load frequency control of power system is one of important subjects in view of system operation and control. That is even though the rapid load disturbances were applied to the given power system, the stable and reliable power should be supplied to the users, converging unconditionally and rapidly the frequency deviations and the tie-line power flow one on each area into allowable boundary limits. Nonetheless of such needs, if the internal parameter perturbation and the sudden load variation were given, the unstable phenomenal of power system can be often brought out because of the large frequency deviation and the unsuppressible power line one. Therefore, it is desirable to design the robust neuro-fuzzy controller which can stabilize effectively the given power system as soon as possible. In this paper the robust neuro-fuzzy controller was proposed and applied to control of load frequency over multi-area power system. The architecture and algorithm of a designed NFC(Neuro-Fuzzy Controller) were consist of fuzzy controller and neural network for auto tuning of fuzzy controller. The adaptively learned antecedent and consequent parameters of membership functions in fuzzy controller were acquired from the steepest gradient method for error-back propagation algorithm. The performances of the resultant NFC, that is, the steady-state deviations of frequency and tie-line power flow and the related dynamics, were investigated and analyzed in detail by being applied to the load frequency control of multi-area power system, when the perturbations of predetermined internal parameters. Through the simulation results tried variously in this paper for disturbances of internal parameters and external stepwise load stepwise load changes, the superiorities of the proposed NFC in robustness and adaptive rapidity to the conventional controllers were proved.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.524-527
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• 2004

New concept of hybrid divisible load theory is introduced in this paper. Hybrid system deals with a combination of modularly divisible load and arbitrarily divisible load. Main idea of hybrid divisible load theory is introduced with a simple example. A condition of optimality is derived for the hybrid case.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2004년도 하계학술대회
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• pp.338-341
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• 2004

New concept of hybrid divisible load theory is introduced in this paper. Hybrid system deals with a combination of modularly divisible load and arbitrarily divisible load. Main idea of hybrid divisible load theory is introduced with a simple example. A condition of optimality is derived for the hybrid case.

• 전기학회논문지
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• 제58권8호
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• pp.1463-1471
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• 2009

In this paper, a new algorithm of Integrated Volt/Var Control (IVVC) is proposed using Volt/Var control for the Distribution Automation System (DAS) based on the modeling of the distributed load and the distributed current. In the proposed, the load flow based on the modeling of the distributed load and the distributed current are estimated from constants of four terminals using the measurement of the current and power factor from a Feeder Remote Terminal Unit (FRTU). For Integrated Volt/Var Control (IVVC), the gradient method is applied to find optimal solution for tap and capacity control of OLTC (On-Load Tap Changers), SVR (Step Voltage Regulator), and SC (Shunt Condenser). What is more Volt/Var control method is proposed using moving the tie switch as well as IVVC algorithm using power utility control. In the case studies, the estimation and simulation network have been testified in Matlab Simulink.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.404-408
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• 2000

The novel control method of ZVS Full-bridge PWM converter with pulse load current is proposed. This new control method can reduce the switching loss of switches during no load condition. Moreover by using feed-forward load current information this method can obtain better transient dynamics compared to the system with only linear feedback control.

• 설비공학논문집
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• 제27권1호
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• pp.50-56
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• 2015

Korea district heating systems have mainly used setting temperature control and outdoor reset control. Different from such conventional normal methods, a thermal-load control proposed in Sweden can decrease the return temperature and reduce pump power consumptions because the control is able to provide the appropriate amount of required heat. In this study, further improved predictive optimal control in addition to the conventional controls were simulated in order to verify its effect in district heating system using TRNSYS 17. $200m^2$ apartment housing which accounts for 25% in Korea and is used as a calculation model;. the number of households in the simulation was 9. As a result, a higher temperature difference and decreasing flow rate at primary loop were shown when using thermal-load control.

• Journal of Power Electronics
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• 제14권1호
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• pp.105-114
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• 2014

The sliding mode control (SMC) strategy is applied to a permanent magnet synchronous machine vector control system in this study to improve system robustness amid parameter changes and disturbances. In view of the intrinsic chattering of SMC, a current sliding mode control method with a load sliding mode observer is proposed. In this method, a current sliding mode control law based on variable exponent reaching law is deduced to overcome the disadvantage of the regular exponent reaching law being incapable of approaching the origin. A load torque-sliding mode observer with an adaptive switching gain is introduced to observe load disturbance and increase the minimum switching gain with the increase in the range of load disturbance, which intensifies system chattering. The load disturbance observed value is then applied to the output side of the current sliding mode controller as feed-forward compensation. Simulation and experimental results show that the designed method enhances system robustness amid load disturbance and effectively alleviates system chattering.

• 한국위성정보통신학회논문지
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• 제10권4호
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• pp.113-116
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• 2015

건물 외부에 설치된 각종 기상 측정센서에서 전송된 현재의 외부 기상조건과 일자별, 특수일별 건물 에너지 사용량과의 관계를 인공지능기법으로 분석하고 학습을 통한 예측기능을 갖도록 함으로써, 일자별, 특수일별, 계절별 그리고 기상조건에 따른 익일 전력 사용량을 예측하고 이에 따른 부하의 On/Off 우선순위를 결정하는 기능을 갖는 지능형 직접부하제어 시스템 구조를 설계한다.

• 융합신호처리학회논문지
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• 제8권2호
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• pp.119-123
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• 2007

본 논문은 유도전동기의 센서리스 속도제어기에 대한 연구이다. 유도전동기의 속도의 제어방법은 자속추정을 위한 기준모델로써 부하-토크 관측기를 이용한 MRAS(Model Reference Adaptive System)를 기초로 하였으며, 전형적인 MRAS 제어기 특성의 속도응답은 부하 토크 외란의 변화에 영향을 미친다. 따라서 제안된 시스템에서의 부하-토크 관측기를 사용한 속도제어 특성은 부하 토크 외란에 의한 영향을 받지 않는다. 이러한 제어 알고리즘을 MATLAB의 SIMULINK를 통해 전체 시스템을 모델링하여 시뮬레이션 한 결과는 유도 전동기의 다양한 부하 구동 적용에 대한 슬라이딩 속도 제어기의 효과적인 개선이 되었음을 알 수 있었다. 그러므로 이러한 제어 방법들이 산업 응용분야에 확대되어 적용되었으면 한다.

• 한국정보통신학회논문지
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• 제22권1호
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• pp.131-139
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• 2018

최근 4차 혁명과 연계하여 많은 선박 분야의 연구들이 수행되고 있으며, 그 중 하나로 에너지 관리시스템 (EMS: Energy Management System)이 관심을 받고 있다. 에너지 관리시스템은 선박의 에너지를 관리하기 위한 시스템을 통칭하며, 다양한 시스템을 포함한다. 본 논문에서는 선박에서의 에너지 절감 분야를 분석하고, 기관실에서 에너지 절감이 가능한 개별 부하 제어 시스템을 포함한 선박 전력 에너지 관리 시스템을 제안한다. 제안하는 EMS는 PCS (Pump Control System), ERFCS (Engine Room Fan Control System), LCS (Load Control System), HVACS (Heating, Ventilation, Air conditioning Control System)의 개별 부하 제어 시스템을 포함한다. 1차적으로, 제안하는 EMS는 기관실의 개별적인 부하 시스템에서 에너지를 절감한다. 2차적으로는 통합 모니터링 및 제어 시스템을 통해 발전 시스템과 전력 부하 시스템을 적절히 제어하여 에너지를 절감한다.