전력계통의 전압안정도향상을 위한 감시제어시스템 개발

이현철(Hyun-Chul Lee),정기석(Ki-Suk Jeoung),박지호(Ji-Ho Park),백영식(Young-Sik Baek) 대한전기학회 2013 전기학회논문지 Vol.62 No.4

This paper was developed a monitoring and control system to use reactive power control algorithm. This algorithm could be improved voltage stability in power system. This method was controlled the voltage for stability improvement, effective usage of reactive power, and the increase of the power quality. PMS(Power Management System) has been calculate voltage sensitivity, and control reactive power compensation device. The voltage control was used to the FACTS, MSC/MSR(Mechanically Switched Capacitors/Reactors), and tap of transformer in power system. The reactive power devices in power system were control by voltage sensitivity ranking of each bus. Also, to secure momentary reactive power, it had been controlled as the rest of reactive power in the each bus. In here, reactive power has been MSC/MSR. The simulation result, First control was voltage control as fast response control of FACTS. Second control was voltage control through the necessary reactive power calculation as slow response control of MSR/MSR. Third control was secured momentary reactive reserve power. This control was method by cooperative control between FACTS and MSR/MSC. Therefore, the proposed algorithm was had been secured the suitable reactive reserve power in power system.

Power extraction efficiency optimization of horizontal-axis wind turbines through optimizing control parameters of yaw control systems using an intelligent method

Song, Dongran,Fan, Xinyu,Yang, Jian,Liu, Anfeng,Chen, Sifan,Joo, Young Hoon Elsevier 2018 APPLIED ENERGY Vol.224 No.-

<P><B>Abstract</B></P> <P>To optimize the power extraction from the wind, horizontal-axis wind turbines are normally manipulated by the yaw control system to track the wind direction. How is the potential power extraction efficiency of such wind turbines related to the parameter optimization of a yaw control system? We intend to answer this question in this study. First, we develop two control systems, a direct measurement-based conventional logic control (Control system 1), and a soft measurement-based advanced model predictive control (Control system 2). Then, a multi-objective Particle Swarm Optimization-based method is introduced to optimize control parameters and search for the Pareto Front, which represents different potential performance. On this basis, result investigation and analysis are carried out on an electrical yaw system of China Ming Yang 1.5 MW wind turbines based on three wind directions with different variations. Experimental results show that, under a large wind direction variation and with a 14% yaw actuator usage, 0.32% and 0.8% more power extraction efficiency are gained by Control system 1 and 2, respectively, after optimization. The achievable power extraction efficiency for the two yaw control systems goes down when the allowable yaw actuator usage is reduced. For instance, when the yaw actuator usage is 14%, 4.9% and 2%, the efficiency is 97.19%, 96.76% and 96.37% for Control system 1, and is 97.73%, 96.76% and 95.45% for Control system 2, respectively. Therefore, Control system 2 takes precedence over Control system 1 for having higher efficiency when the allowable yaw actuator usage is more than 4.9%. We also find that the potential power extraction efficiency of the two control systems is significantly influenced by the wind direction variation, that is, the optimized efficiency under small wind direction variation is 1.5% higher than that under large wind direction variation. In addition, the parameters of Control system 1 need to be re-optimized according to the wind condition, whereas the ones of Control system 2 may not. Finally, a novel yaw control strategy employing the optimized parameters as the query tables is suggested for the real applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Two favorable yaw control systems are developed and optimized. </LI> <LI> Intelligent optimization method is proposed to optimize the potential performance. </LI> <LI> Power extraction efficiency is optimized by 0.32% and 0.8% for two control systems. </LI> <LI> Optimized efficiency under small wind variation is 1.5% more than the large variation one. </LI> <LI> Novel yaw control strategy employing optimized parameters is suggested. </LI> </UL> </P>

유압변속시스템 기반 가동물체형 파력발전장치의 최대출력제어(MPPT) 알고리즘에 관한 연구

노찬(Roh Chan),박지용(Ji Yong Park),하윤진(Yoon-Jin Ha),천호정(Ho Jung Cheon),김경환(Kyong-Hwan Kim) 한국해양환경·에너지학회 2020 한국해양환경공학회 학술대회논문집 Vol.2020 No.11

본 연구에서는 유압변속시스템 기반 가동물체형 파력발전장치의 최대출력제어(Maximum Power Point Tracking, MPPT) 알고리즘에 관한 연구를 진행하였다. 유압변속시스템을 이용한 동력전달장치(Power Take-Off, PTO)는 저속 고토크 제어가 가능하기 때문에 가동물체형 파력발전장치 PTO 시스템으로 이미 많이 사용되었다. 본 논문에서는 최대출력제어 알고리즘에 따른 유압시스템 기반 PTO 시스템에 대한 특성을 분석하고, 이를 기반으로 입력 파워 및 출력 파워 그리고 PTO 시스템 효율에 대한 분석을 진행하였다. 최대출력제어 알고리즘은 P&O 알고리즘 기반 속도제어 알고리즘과 최적 토크제어 알고리즘을 각각 적용하여 분석하였다. 본 연구 결과를 기반으로 향후 가동물체형 파력발전용 유압시스템 기반 PTO 시스템의 실해역 시험에 최대출력제어 알고리즘에 기초자료로 활용될 것이다. In this study, a study was conducted on the Maximum Power Point Tracking (MPPT) algorithm of a movable object type wave energy converter based on a hydraulic transmission system. Power Take-Off (PTO) using a hydraulic transmission system is already widely used as a movable object type wave energy converter PTO system because it can control low-speed and high torque. In this paper, the characteristics of the hydraulic system-based PTO system according to the maximum power control algorithm were analyzed, and based on this, the input power, output power, and PTO system efficiency were analyzed. The maximum power control algorithm was analyzed by applying the P&O algorithm-based speed control algorithm and the optimal torque control algorithm, respectively. Based on the results of this study, it will be used as basic data for the maximum power control algorithm in the actual sea area test of the PTO system based on the hydraulic system for wave power generation in the future.

The integrated monitoring and control system for the combined cycle power plant

Bong-Kuk Lee,Yong-Hak Shin 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

In this paper, the open and standardized integrated monitoring and control system for the combined cycle power plant was developed and verified. The developed integrated monitoring and control system is monitoring and controlling mainly for the boiler called HRSG(Heat recovery steam generator) and BOP(Balance of plant) and Turbine in the thermal power plant. There were various operating modes frequent start-up and shut-down operations for operating the thermal power plant. Accordingly, the control for the various operating modes and the advanced control for the critical equipments was achieved and developed for the integrated monitoring and control system. As a advanced control algorithm, we adopted a MPC(Model predictive controller) MIMO control method. For the integrated monitoring and control system we developed the standardized and open interface APIs(Application program interface) to connect to other system efficiently and the function of web monitoring system to manage the remote monitoring and real time historical system. The developed system was verified in the real power plant environment.

전력시스템의 부하주파수 제어를 위한 뉴로-퍼지제어기 설계

손태훈,김상효 동의공업대학 2000 論文集 Vol.26 No.1

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 ones of each area into allowable boundary limits. Nonetheless of such needs, if the internal parameter perturbation and the sudden load variation were given, the unstable phenomena 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 power system 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.

석탄화력발전소 보일러 연료제어 알고리즘과 분산제어시스템의 개발

임건표(Gun-Pyo Lim),이흥호(Heung-Ho Lee) 대한전기학회 2013 전기학회논문지 P Vol.62 No.1

This paper is written for the development and application of boiler fuel control algorithm and distributed control system of coal-fired power plant by the steps of design, coding, simulation test, site installation and site commissioning test. Fuel control algorithm has the upper algorithm and it is boiler master control algorithm that controls the fuel, feed water, air by generation output demand. Generation output demand by power load influences fuel control. Because fuel can not be supplied fast to the furnace of boiler, fuel control algorithm was designed adequately to control the steam temperature and to prevent the explosion of boiler. This control algorithms were coded to the control programs of distributed control systems which were developed domestically for the first time. Simulator for coal-fired power plant was used in the test step. After all of distributed control systems were connected to the simulator, the tests of the actual power plant were performed successfully. The reliability was obtained enough to be installed at the actual power plant and all of distributed control systems had been installed at power plant and all signals were connected mutually. Tests for reliability and safety of plant operation were completed successfully and power plant is being operated commercially. It is expected that the project result will contribute to the safe operation of domestic new and retrofit power plants, the self-reliance of coal-fired power plant control technique and overseas business for power plant.

Analysis of Control Conflict between UPFC Multiple Control Functions and Their Interaction Indicator

Wang H. F.,Jazaeri M.,Cao Y. J. Institute of Control 2005 International Journal of Control, Automation, and Vol.3 No.S

Interactions among multiple control functions of a UPFC installed in a power system have been observed in power system simulation and been reported in authors' previous publications [1,2]. This paper presents new analytical results about these observed interactions and concludes that they are due to the control conflict between the series and shunt part of the UPFC, which are connected through the internal common capacitor inside the UPFC. Investigation in the paper reveals, for the first time as far as the authors are aware of, that the linkage pattern of UPFC series and shunt part decides whether the control functions implemented by the UPFC series and shunt part conflict each other or not. This linkage pattern of UPFC series and shunt part can be described by the flow of active power through the UPFC at steady-state operation of the power system. Hence in order to predict the possible interactions among multiple control functions of the UPFC, an interaction indicator is proposed in the paper which is the direction and amount of active power flow through the internal link of the UPFC series and shunt part at steady-state operation of the power system. This proposed interaction indicator can be calculated from power system load flow solution without having to run simulation of the power system with UPFC controllers installed. By using the indicator, the interactions among multiple control functions of the UPFC caused by badly set controller's parameters are excluded. Therefore the indicator only identifies the possible existence of inherent control conflict of the UPFC.

Analysis of Control Conflict between UPFC Multiple Control Functions and Their Interaction Indicator

H. F. Wang,M. Jazaeri,Y. J. Cao 대한전기학회 2005 International Journal of Control, Automation, and Vol.3 No.2

Interactions among multiple control functions of a UPFC installed in a power system have been observed in power system simulation and been reported in authors' previous publications [1,2]. This paper presents new analytical results about these observed interactions and concludes that they are due to the control conflict between the series and shunt part of the UPFC, which are connected through the internal common capacitor inside the UPFC. Investigation in the paper reveals, for the first time as far as the authors are aware of, that the linkage pattern of UPFC series and shunt part decides whether the control functions implemented by the UPFC series and shunt part conflict each other or not. This linkage pattern of UPFC series and shunt part can be described by the flow of active power through the UPFC at steady-state operation of the power system. Hence in order to predict the possible interactions among multiple control functions of the UPFC, an interaction indicator is proposed in the paper which is the direction and amount of active power flow through the internal link of the UPFC series and shunt part at steady-state operation of the power system. This proposed interaction indicator can be calculated from power system load flow solution without having to run simulation of the power system with UPFC controllers installed. By using the indicator, the interactions among multiple control functions of the UPFC caused by badly set controller's parameters are excluded. Therefore the indicator only identifies the possible existence of inherent control conflict of the UPFC.

Application of Fuzzy PI Control Algorithm as Stator Power Controller of a Double-Fed Induction Machine in Wind Power Generation Systems

Gyo-Bum Chung,Jaeho Choi 전력전자학회 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.1

This paper addresses the output control of a utility-connected double-fed induction machine (DFIM) for wind power generation systems (WPGS). DFIM has a back-to-back converter to control outputs of DFIM driven by the wind turbine for WPGS. To supply commercially the power of WPGS to the grid without any problems related to power quality, the real and reactive powers (PQ) at the stator side of DFIM are strictly controlled at the required level, which in this paper is realized with the Fuzzy PI controller based on the field orientation control. For the Sinusoidal Pulse Width Modulation (SPWM) converter connected to the rotor side of DFIG to maintain the controllability of PQ at the state side of DFIM, the DC voltage of the DC link capacitor is also controlled at a certain level with the conventional Proportion-Integral (PI) controller of the real power. In addition, the power quality at the grid connected to the rotor side of DFIM through the back-to-back converter is maintained in a certain level with a PI controller of the reactive power. The controllers for the PQ at the stator side of DFIM, the DC link voltage of the back-to-back inverter and the reactive power at the grid connected to the rotor side of DFIM are designed and simulated in the PSIM program, of which the result verifies the performance of the proposed controllers.

Direct Parallel and Hybrid Power Control Scheme of a Low-Power PV and Piezoelectric Energy Harvesting Module

Lee Dong-Hee 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.4

This paper presents a novel direct parallel power control scheme with independent current paths for the proposed hybrid energy-harvesting system that consists of a low-power photovoltaic panel, a piezoelectric harvesting module, and an energy storage system. A battery is connected to store the generated power from the two renewable power sources to provide a continuous power supply for the users. The designed power converter controls both battery state and power supply without any power conditioning system. To achieve this, a low-power DC–DC converter with battery charging function and control algorithm is designed for the hybrid power source. Therefore, in the proposed system, no additional battery charge controller is required. To control the battery, however, an additional current sensor to detect the battery power is simply added to each DC–DC converter. In the proposed power control scheme and controller, each power input, output, and the combined power fl ow are connected with neither communication protocols nor additional controller. Moreover, the converters can adjust the supplied power for parallel power-sharing. For maximum output current protection in each converter and constant current control for the battery, a hybrid power connection and its related current path are also proposed in this paper. The eff ectiveness of the proposed hybrid power system and the direct parallel power control scheme was verifi ed through experiments.