Plenary 1: Prof. Hsiao-Dong Chiang (Cornell University, USA), "Feasible Region of Optimal PowerFlow:Theory, Methods, Bifurcations and Applications"

 

Abstract:The feasible region plays a fundamental role in solving optimal power flow (OPF) problems.  OPF solutions do not exist if the corresponding feasible region is an empty set. Any solution algorithm proposed for solving OPF problems will fail if the feasible region does not exist. In addition, the geometry and characteristics of feasible region indeed affect the performance of OPF solution methods. In this talk, a complete characterization of the feasible region of OPF problems will be presented. This mathematical characterization can lead to the development of numerical methods for computing feasible solutions. It will be shown that the feasible region of a general OPF problem equals the union of regular stable equilibrium manifolds of a non-hyperbolic dynamical system that is constructed from the set of equality and inequality constraints of the OPF problem. It will be further shown that the non-hyperbolic dynamical system is completely stable. This complete stability property allows one to locate multiple points lying on stable equilibrium manifolds via trajectories of the non-hyperbolic dynamical system, which can be useful for practical applications. Bifurcation analysis of feasibility region due to varying loading conditions will be presented to explain several challenges encountered in practical applications. The notion of a local feasible region will be introduced for large-scale OPF problems for visualization of feasible components and local optimal solutions. A numerical method for identifying the existence/non-existence of feasible solution for an OPF problem will be presented and illustrated on large-scale OPF problems.

 

Hsiao-Dong Chiang (M’87–SM’91–F’97) received the Ph.D. degree in electrical engineering and computer sciences from the University of California at Berkeley, Berkeley, CA, USA. Since 1998, he has been a Professor in the School of Electrical and Computer Engineering at Cornell University, Ithaca, NY, USA. His current research interests include nonlinear systems, power networks, nonlinear computation, nonlinear optimization, and their practical applications. He and his team members have published more than 400 referred papers with the H factor of 51. He holds 20 U.S. and overseas patents and several consultant positions. He is the author of two books: Direct Methods for Stability Analysis of Electric Power Systems: Theoretical Foundations, BCU Methodologies, and Applications (Hoboken, NJ, USA: Wiley, 2011) and (with Luis F. Alberto) Stability Regions of Nonlinear Dynamical Systems: Theory, Estimation, and Applications (Cambridge, UK: Cambridge Univ. Press, 2015). He has served as an associate editor for three different IEEE transactions and journals, and served as a board member for IEEJ Japan, and is the founder and President of Bigwood Systems, Inc., and of Global Optimal Technology, Inc., Ithaca, NY, USA.

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Plenary 2: Prof. Sukumar Mishra (IIT-Delhi, India),"Ancillary Services by Photo Voltaic  (PV) Energy Conversion Systems"

 

Abstract: The term ancillary services is used to refer to a variety of operations beyond generation and transmission that are required to maintain grid stability and security. These services generally include reactive power and voltage control, active power and frequency control, mitigation of energy imbalance, harmonic mitigation etc. One of the benefits in large scale grid integration of renewables is the potential of ancillary support to the grid. The talk will discuss control methodologies for renewable energy sources. A brief description will be presented on how renewable energy sources, particularly solar photo voltaic (PV) energy conversion systems, can be used as an ancillary service provider.

The talk will give insight to the following points:

• Reactive power generation by voltage source converters (VSC), capability curve of VSC, application of solar PV for reactive power and frequency control.

• Concept of de-loaded (also known as de-rated) PV and control of solar PV systems for primary frequency regulation and for secondary frequency regulation using de-rating or using PV with energy storage.

• The control of PV inverters to inject negative sequence current in the system so as to minimize the voltage unbalance in a microgrid which are caused by unbalanced load particularly during islanding.

• The concept of Virtual Harmonic Impedance and the control of solar PV as virtual harmonic impedance to compensate residential system harmonics and thereby improving the power quality.

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Sukumar Mishra is a Professor in the Department of Electrical Engineering at the Indian Institute of Technology Delhi. His interest lies in the field of Power Systems, Power Quality Studies, and Renewable Energy. He has published over 100 research articles (including papers in international journals, conferences and book chapters).

He is currently holding the position of Vice Chair of Intelligent System Subcommittee of Power and Energy society of IEEE. He is a recipient of the INSA medal for young scientist, the INAE young engineer award, and the INAE silver jubilee young engineer award. He is also a Fellow of IET (UK), NASI (India), INAE (India), IETE (India) and IE (India).

He is actively involved in academic and industrial collaboration for research and development. He is working as the NTPC Chair professor and has previously worked as the Power Grid Chair professor. He is also serving as an Independent Director of the Cross Border Power Transmission Company Ltd. and the River Engineering Pvt. Ltd. He is also recognized as the INAE Industry Academic Distinguish Professor. He has handled many research projects and industrial consultancies. He has a vast experience of 25 years and he is currently serving as an Editor for the IEEE Transactions on Smart Grid and an Associate Editor for the IET Generation, Transmission & Distribution journal.

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Plenary 3: Prof. Jaeseok Choi (Gyeonsang National University, Korea), "ProbabilisticSimulation Methodologies of Power System Considering RenewableEnergy Generators"

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Abstract: In recently, the probabilistic generating simulation considering renewable energy generators as well as BESS(Battery Energy Storage System) device system plays a key role in expansion planning and operating scheduling of generation system considering renewable generators. Under high penetrated renewable energy generation system environment, probabilistic production expected energy, loss of load probability and unserved energy through computer simulation are extreme important because the evaluation simulation model can permit optimal capacity and reasonable design for organizing smart grid, micro grid as well as super grid. For conventional generation system as like as nuclear and thermal generators, many studies for this area have been done for these purposes in last 60 years. They differ in the way of representing the equivalent load duration curve (ELDC). They can be categorized either exact methods (Booth-Baleriaux method) or approximation methods (Cumulant method and Mixture of Normals Approximation (MONA)), Monte Carlo simulation approach. etc. In Booth-Baleriaux method, the ELDC is represented by a uniformly spaced grid. The successive ELDC is evaluated at each grid point. Using Booth-Baleriaux method, the PraWin and PraSol simulation algorithms which can consider wind generation and solar generation (PV: Photo Voltaic) is developed and introduced. Furthermore, case studies in Korea will be demonstrated in order to evaluate economic value and reliability. Additionally, this keynote proposes a new method for evaluating Effective Load Carrying Capability(ELCC) and Capacity Credit(C.C.) of power system including Wind Turbine Generator(WTG) combined with BESS. WTG can only generate electricity power when the fuel(wind) is available. Because of fluctuation of wind speed, WTG generates intermittent power. In view point of reliability of power system, intermittent power of WTG is similar with probabilistic characteristics based on power on-off due to mechanical availability of conventional generator. Therefore, high penetration of WTG will occur difficulties in power operation. The high penetration of numerous and large capacity WTG can make risk to power system adequacy, quality and stability. Therefore, the penetration of WTG is limited in the world. This study develops a new method to assess how much is high penetration of WTG able to extended when WTG is combined with BESS. This paper demonstrates a various case studies of ELCC and C.C. of power system containing WTG combined with BESS using model system as similar as Korea power system. This algorithm can be applied as same style as like as WTG.

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Jaeseok Choi (S’88–M’91–SM’05, IEEE) was born at Gyeongju, Korea on 1958. Obtained B.Sc, M.Sc and Ph.D degrees from Korea University in 1981, 1984, 1990 respectively. His research interest includes Ambiguity Theory Applications, Probabilistic Production Cost Simulation, Reliability Evaluation, Outage Cost Assessment and Expansion Planning of Power Systems. Since 1991, he has been a faculty of Gyeongsang National University where is a full professor. He has been a Post-Doctor at University of Saskatchewan in Canada on 1996. He was visiting professor at Cornell University, USA in 2004 to 2006. He is also adjunct professor of Illinois Institute of Technology, Chicago, IL, USA since 2007. He is a senior member of IEEE and KIEE since 2005. He was Editor-in Chief of JEET(Journal of Electrical Engineering and Technology) of KIEE since 2012~2014.  He was president of KIEE PES in 2016. He is vice-president of KIEE since 2017. Over 450 papers including following International Conferences papers published until 2018 were written by him.

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Plenary 4: Prof. Ying-Yi Hong (Chung Yuan Christian University, Taiwan), "Taguchi Method Applied to Power and Energy Studies"

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Abstract:“Design of Experiment” (DOE) is a statistical technique that is used in studying the overall effect of multiple variables on the output. The quality engineering method, which was proposed by Dr. Genechi Taguchi, is commonly known as the Taguchi method. The Taguchi method has been used not only for quality engineering but also to study electrical engineering problems, such as motor design, battery charging and transmission network expansion problems.

 

This speech will introduce three applications of Taguchi method in the areas of power and energy engineering as follows. 

(1) Taguchi Method-based Probabilistic Load Flow Studies Considering Uncertain Renewables and Loads: This method utilizes a few deterministic load flow solutions obtained using Taguchi’s orthogonal array to estimate the means and standard deviations of bus voltages, phase angles, line flows, and other metrics.  A deterministic load flow calculation corresponds to an experiment in Taguchi’s method.  A 25-bus standalone power system and a modified IEEE 118-bus system in which wind-turbine generators generate uncertain power are tested.

(2) Optimal Design of IT2-FCS-based STATCOM Controller Applied to Power System with Wind Farms Using Taguchi Method: This work presents a novel interval type-II fuzzy control system (IT2 FCS)-based controller for the STATCOM to stabilize bus voltages that are caused by faults or forced wind farm outages in a smart grid. Since many possible scenarios may arise in the power system, the Taguchi method is used to design experiments using an orthogonal array, in which all scenarios are mutually independent. 

(3) A Robust Design of Maximum Power Point Tracking (MPPT) Using Taguchi Method for Stand-Alone PV System: This work proposes a novel robust design, which relies on different combinations of insolations, temperatures, and tilt angles, for implementing MPPT in a stand-alone PV system. Orthogonal experiments are performed using Taguchi method in multiple scenarios, avoiding the full factorial design of experiments.

 

Ying-Yi Hong received his B.S.E.E and M.S.E.E. degrees from the Chung Yuan Christian University (CYCU) and the National Cheng Kung University, Taiwan, in 1984 and 1986, respectively. Sponsored by the Ministry of Education of Taiwan, he conducted research in the Department of E.E. at the University of Washington, Seattle, from August 1989 to August 1990. He received his Ph.D. degree from the Institute of E.E. in December 1990 from the National Tsing-Hua University, Taiwan. Professor Hong is an IEEE senior member and an IET Fellow.  He was the Chair of the IEEE Power Engineering Society Taipei Chapter in 2001 and 2002 and was the Vice Chair of IEEE Taipei Section in 2013-2014. He also received the Outstanding Electrical Engineering Professor Award from the Chinese Institute of Electrical Engineering in 2006. Professor Hong serves as a referee for the IEEE Trans. on Power Systems, Power Delivery, Energy Conversion, Smart Grid, Industrial Informatics, Industrial Applications and Industrial Electronics.  He also helps review the papers submitted to IEE (IET) Proceedings of Generation, Transmission and Distribution as well as Electric Power Systems Research, Electric Power Energy Systems, IEEE PES Letters, Applied Energy, Energy, Solar Energy and Soft Computing, etc. Since 1991, Professor Hong has chaired/cochaired more than 100 projects sponsored by National Science Council, Taipower, Bureau of Energy, Ministry of Economic Affairs, Institute of Nuclear Energy Research, or Institute for Information Industry. Professor Hong chaired the Taipower’s first project related to the deregulated power market in 1996. Professor Hong led a project team from 5 universities to propose a revised Transmission Expansion Code for Taipower in 2002. He chaired a project supported by Bureau of Energy to revise 8 Sub-electricity Acts in 2004.  Up to now, he published 98 SCI journal papers, 200 conference papers, conducted 4 technology transfers and gained 10 patents. From 2006~2012 and 2012~2018, he was the Dean of College of EECS and Secretary General at CYCU, respectively. He was promoted to be a distinguished professor in 2012 due to his exceptional performance in research, leadership, team work and international collaboration.  At present, he serves as a Dean of Research and Development at CYCU.

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