1 EMTP Simulation of a STATCOM-Shunts- OLTC Coordination for Local Voltage Control K. S. Jeong ★ , Y. S. Baek ★ , J. S. Yoon ★★ , B. H Chang ★★ , H. C. Lee ★★★ , G. J. Lee ★★★★ ★ Kyungpook Univ, ★★ KEPRI, ★★★ GreenNetPower, ★★★★ Chungbuk Provincial Univ. Abstract--This paper proposes coordinative control method between STATCOM installed within substation and other reactive power resources including Shunt Reactors and Shunt Capacitors and OLTC. Voltage/Reactive power control has various difficult aspects to control because of analysis and system dynamics error. This coordinative control method suggests practical algorithm regarding system voltage and reactive power status which is easy to implement in substation basis. In normal status, STATCOM- Shunts-OLTC are in operation. The proposed algorithm is tested and verified in EMTP/RV. And this is expected to be applied to control multiple reactive power devices combined with SCADA/EMS system. Index Terms-- EMTP Modeling, External Bank, Tap Changer, Coordinative Control, STATCOM, Local Voltage Control I. INTRODUCTION orea power system is required to a large size of facilities and high power technology according to increasing power demand. However, the rapid changes of power market and weighted difficulties of expanding power facilities requires to new technology. Installation of FACTS (Flexible AC Transmission System) device can maximize utilization of existing power facilities and reliability of power system. The controllers which have a wide range of applicability can be extensively applied to power and voltage control of power system. In this situation, Korea power system has installed several FACTS devices, SVC (Static Var Compensator) at Yang-ju substation, UPFC operated at Gang-jin substation and HVDC operated at Hae-nam substation and so on. 345kV 100MVA STATCOM that will be installed in MIGUM substation is first localized facilities of large- capacity FACTS facilities in Korea power system. STATCOM provides similar ability and dynamic characteristic as synchronous condenser that is facilities of reactive power control. However, STATCOM has excellent characteristics in operating cost, maintaining facilities, loss, installing scale to consist static power electronics facilities (inverter) different from synchronous condenser. However, STATCOM has a disadvantage of facility cost over capacity. Therefore it is effective to coordinate STATCOM and existing capacitor and reactor bank with mechanical switch. However these facilities are no enough to operate coordinative control with existing external bank (shunt reactor, shunt capacitor) and OLTC (On Load Tap Changer) and so on. So it is required to improve the ability to respond to voltage instability in an emergency, not keep voltage stability normally. After the 1987 Tokyo Blackout, Japanese power system engineers have steadily studied development and installation of advanced reactive power facilities and coordinative control method between FACTS and reactive power sources for improvement of voltage stability. The event of Gu-mi is similarly applied to the coordinative control method by FACTS installation. This paper mainly proposes coordinative control method between STATCOM installed within substation and phase modifying equipment including shunt reactor and shunt capacitor when system voltage reference is given. We rarely analyzed the system configuration with a large error of reactive power characteristic analysis of power system except we need. And output of control parameters are set up with voltage variation and characteristic of and phase modifying equipment. The proposed coordinative control method is developed for the STATCOM of MIGUM substation and the simulation results of EMTP/RV model show the effectiveness of the proposed method. K. S. Jeong is with School of Electrical Engineering and Computer Science, Kyungpook National University, Daegu 702-701, Korea ( e-mail: biotronic@naver.com ). Y. S. Baek is with School of Electrical Engineering and Computer Science, Kyungpook National University, Daegu 702-701, Korea ( e-mail: ysbaek@knu.ac.kr ). II. STATCOM-SHUNTS-OLTC COORDINATION B. H. Chang is a senior Researcher of Power System Lab at KEPRI, 305- 762, Korea ( e-mail : Jang7@kepco.co.kr ) J. S. Yoon is a senior Researcher of Power System Lab at KEPRI, 305-762, Korea ( e-mail : JSyoon@kepco.co.kr ) G. J. Lee is with the Department of Electrical Engineering, Chunbuk Provincial Collage, Chungbuk, Korea. ( e-mail: roundyou@hotmail.com ). H. C. Lee is with the Department of R&D, GreenNetPower Co., Okchun, Korea . ( e-mail: oneye1@naver.com ). Local reactive power control method of substation which has FACTS controller (STATCOM) and other reactive power controllers. The coordinative control between STATCOM, external bank and OLTC on a substation level is illustrated in Fig. 1. The reference voltage, reference reactive power and K IEEE T&D Asia 2009