Byung-Hoon Chang

Development of FACTS operation technology to the KEPCO power network-installation and operation

KEPRI, the research institute of Korean Electric Power Corporation (KEPCO), has been investigating the feasibility of applying inverter type FACTS equipment into the local power system through a series of research projects. Based on the results, KEPCO has been working on a 80 MVA UPFC pilot plant (PP) project to be applied to the 154 kV system with a consortium formed with Hyosung Corporation, Siemens, and local research institutes since April, 2000. Through the knowledge and experience gained in application, installation, and operation of inverter type FACTS equipment on an actual 154 kV power system, KEPCO plans to derive the specifications and operation strategies needed to apply similar equipment to the 345 kV transmission system which is the backbone of the Korean power system.. This paper introduces the distinct features of the Korean power system, characteristics of the surrounding power system near the pilot plant installation site, equipment specifications, construction methods for application and operation of FACTS equipment to the local system, and future research plans.

A Novel Operation Strategies for Shunt-Type FACTS Controllers in the KEPCO System

In this letter, the application schemes for a coordinated control system of multiple FACTS controllers are presented to enhance the voltage stability around the Seoul metropolitan area. To coordinate the control of FACTS devices, fV analysis was performed with real-time network data transferred from the SCADA/EMS system. First, the fV analysis method is performed for the contingency set. Then the new operational setpoint is calculated with the VQ analysis method if it is deemed necessary to increase the margin of stability for a specific contingency. Consequently, the security of the power system is enhanced with a coordinated control system of multiple FACTS controllers and analyzed with a year 2007 SCADA/EMS data.

Development of FACTS operation technology to the KEPCO power network-detailed EMTDC model of 80 MVA UPFC

This paper describes the development of the electromagnetic transient model of 80 MVA KEPCO UPFC and the analysis of its performance in the actual Korea power system. KEPCO, Korea Electric Power Corporation, 80 MVA UPFC is now under installation and ready for commercial operation from the year 2003. In order to apply a new control device as UPFC for actual power system, the utility should study not only load flow and stability level, but also EMTP and EMTDC level in advance. Therefore, KEPRI, the research institute of KEPCO, developed the detailed transient analysis model that is based on the actual UPFC S/W algorithm and H/W specification. This simulation model is implemented by an EMTDC/PSCAD package. The results of simulation show the effectiveness of UPFC operation in the KEPCO power system.

A Study on the Criteria for Setting the Dynamic Control Mode of Battery Energy Storage System in Power Systems

This paper presents the criteria for setting the dynamic operating mode of BESS(Battery Energy Storage System) in the bulk power systems. ESS has been expected to improve the degraded dynamic performance of the power system with high penetration of the renewable resources. While ESS is controlled in steady state or dynamic operating mode for its better effectiveness depending on the operating conditions of power systems, the criteria for setting the dynamic operating mode for the transient period needs to be robust enough to cover all the different conditions. The proposed criteria consider the varying conditions and the operating practices of the bulk power systems.This paper presents the criteria for setting the dynamic operating mode of BESS(Battery Energy Storage System) in the bulk power systems. ESS has been expected to improve the degraded dynamic performance of the power system with high penetration of the renewable resources. While ESS is controlled in steady state or dynamic operating mode for its better effectiveness depending on the operating conditions of power systems, the criteria for setting the dynamic operating mode for the transient period needs to be robust enough to cover all the different conditions. The proposed criteria consider the varying conditions and the operating practices of the bulk power systems.

Development of Reliability Contribution Function of Power System including Wind Turbine Generators combined with Battery Energy Storage System

Abstract - This paper presents a study on reliability assessment and new contribution function development of power system including Wind Turbine Generator(WTG) combined with Battery Energy Storage System(BESS). This paper develops and proposes new reliability contribution function of BESS installed at wind farms. The methodology of reliability assessment, using Monte Carlo Simulation(MCS) method to simulate sample state duration, is proposed in detail. Forced Outage Rate(FOR) considered probabilistic approach for conventional generators is modelled in this paper. The penetration of large wind power can make risk to power system adequacy, quality and stability. Although the fluctuation of wind power, BESS installed at wind farms may smooth the wind power fluctuation. Using small size system as similar as Jeju island power system, a case study of reliability evaluation and new proposed contribution function of power system containing WTG combined with BESS is demonstrated in this paper, which would contributes to BESS reliability contribution and assessment tools of actual power system in future. Key Words : Wind turbine generator(WTG), Battery energy storage system(BESS), Monte carlo simulation(MCS), Reliability evaluation, ESS reliability contribution † Corresponding Author : Dept. of Electrical Eng., RIGET, ERI, Gyeongsang National University, Korea E-mail : jschoi@gnu.ac.kr* Dept. of Electrical Engineering, Gyeonsang National University , Korea ** KEPRI, KEPCO*** Dept. of Electrical Engineering, Daejin University, Korea Received : September 9, 2015; Accepted : February 19, 2016

Reliability Evaluation with Wind Turbine Generators and an Energy Storage System for the Jeju Island Power System

This paper proposes probabilistic reliability evaluation model of power system considering Wind Turbine Generator(WTG) integrated with Energy Storage System(ESS). Monte carlo sample state duration simulation method is used for the evaluation. Because the power output from WTG units usually fluctuates randomly, the power cannot be counted on to continuously satisfy the system load. Although the power output at any time is not controllable, the power output can be utilized by ESS. The ESS may make to smooth the fluctuation of the WTG power output. The detail process of power system reliability evaluation considering ESS cooperated WTG is presented using case study of Jeju island power system in the paper.

EMTDC Simulation Model for FACTS Device

This paper describes the impact of the FACTS application on the power network using EMTDC simulation package. KEPCO (Korea Electric Power Corporation) has begun the operation of the plusmn80 MVA UPFC (unified power flow controller) from the year 2003 on the 154 kV transmission system. The UPFC consists of two voltage source inverters (VSI), STATCOM and SSSC, which are connected through a common DC link capacitor. Through a combination of both VSIs, the UPFC can control bus voltage, real and reactive power flow. But, in some cases, each VSI can be operated independently according to operation modes. After all, The UPFC can be operated 3 operation mode; SSSC, STATCOM and UPFC mode. The paper describes the fundamental operating effects and basic control approach of a SSSC mode operation of KEPCO UPFC to the power system

Demonstration to Operate and Control Frequency Regulation of Power System by 4MW Energy Storage System

Abstract - Operation and control system has been installed and tested to use energy storage system(ESS) for frequency regulation at 4MW class of ESS demonstration facility installed at Jeju island, Korea in 2013. Simulation tests were performed by programing language C# for power system of Jeju island to develop control algorithm. Site simulation tests were performed in control system itself without connecting power system and energy storage system. Control algorithm was coded, modified and tested to load to controller and communication system and human-machine interface were developed and tested in the process of simulation tests. After similar results to that of simulation tests by programing language were obtained, power system and energy storage system demonstration facility were connected to control system by communication system. Energy storage system for frequency regulation was tested for actual frequency and simulation frequency. The site tests showed the similar results to that of simulation tests and the control systems is possible to be operated for frequency regulation. Faster response of energy storage system for frequency regulation, less costs and less capacity of energy storage systems which cover for frequency regulation of power plants. It is expected that more studies for time-reduction and time-delay elements can make less capacity of energy storage system cover more role of frequency regulation of power plants.Key Words : Energy storage system, Frequency regulation, Power system, Control†Corresponding Author : Korea Electric Power Corporation Research Institute E-mail : kepcolim@kepco.co.kr*Korea Electric Power Corporation Research Institute, Korea 접수일자 : 2014년 6월 10일수정일자 : 2014년 7월 27일 최종완료 : 2014년 8월 20일Operation and control system has been installed and tested to use energy storage system(ESS) for frequency regulation at 4MW class of ESS demonstration facility installed at Jeju island, Korea in 2013. Simulation tests were performed by programing language C# for power system of Jeju island to develop control algorithm. Site simulation tests were performed in control system itself without connecting power system and energy storage system. Control algorithm was coded, modified and tested to load to controller and communication system and human-machine interface were developed and tested in the process of simulation tests. After similar results to that of simulation tests by programing language were obtained, power system and energy storage system demonstration facility were connected to control system by communication system. Energy storage system for frequency regulation was tested for actual frequency and simulation frequency. The site tests showed the similar results to that of simulation tests and the control systems is possible to be operated for frequency regulation. Faster response of energy storage system for frequency regulation, less costs and less capacity of energy storage systems which cover for frequency regulation of power plants. It is expected that more studies for time-reduction and time-delay elements can make less capacity of energy storage system cover more role of frequency regulation of power plants.

Centralized Control Algorithm for Power System Performance using FACTS Devices in the Korean Power System

This paper presents a centralized control algorithm for power system performance in the Korean power system using Flexible AC Transmission Systems (FACTS) devices. The algorithm is applied to the Korean power system throughout the metropolitan area in order to alleviate inherent stability problems, especially concerns with voltage stability. Generally, control strategies are divided into local and centralized control. This paper is concerned with a centralized control strategy in terms of the global system. In this research, input data of the proposed algorithm and network data are obtained from theSCADA/EMS system. Using the full system model, the centralized controller monitors the system conditionand decides the operating point according to the control objectives that are, in turn, dependenton system conditions. To overcome voltage collapse problems, load-shedding is currently applied in the Korean power system.In this study, the application of the coordination between FACTS and switch capacitor (SC) canrestore the solvability without load shedding or guarantee the FV margin when the margin is insufficient.Optimal Power Flow (OPF) algorithm, for which the objective function is loss minimization, isused in a stable case. The results illustrate examples of the proposed algorithm using SCADA/EMS data of the Korean power system in 2007.

Development of FACTS operation technology to the KEPCO power network-development of education program for 80 MVA UPFC operator

KEPRI has been working on a 80 MVA UPFC pilot plant (PP) project to be applied to the 154 kV system with a consortium formed with Hyosung Corporation and Siemens since April, 2000. KEPRI, the research institute of Korean Electric Power Corporation (KEPCO), has been studying the operation strategy for KEPCO 80 MVA UPFC. This paper introduces the results of on-line emulator development for the operator education at the KEPCO UPFC site.