FUZZY SATISFYING INTERACTIVE MULTIOBJECTIVE THERMAL POWER DISPATCH： SWT APPROACH

In multiobjective optimization, trade-off analysis plays an important role in determining most preferred solution. This paper presents an explicit interactive trade-off analysis based on the surrogate worth trade-off function to determine the best compromised solution. In the multiobjective framework thermal power dispatch problem is undertaken in which four objectives viz. cost, NOx emission, SOx emission and COx emission are minimized simultaneously. The interactive process is implemented using a weighting method by regulating the relative weights of objectives in systematic manner. Hence the weighting method facilitates to simulate the trade-offrelation between the conflicting objectives in non-inferior domain. Exploiting fuzzy decision making theory to access the indifference band, interaction with the decision maker is obtained via surrogate worth trade-off （SWT） functions of the objectives. The surrogate worth trade-off functions are constructed in the functional space and then transformed into the decision space, so the surrogate worth trade-off functions of objectives relate the decision maker＇s preferences to non-inferior solutions through optimal weight patterns. The optimal solution of thermal power dispatch problem is obtained by considering real and reactive power losses. Decoupled load flow analysis is performed to find the transmission losses. The validity of the proposed method is demonstrated on 11-bus, 17-lines IEEE system, comprising of three generators.

Fuzzy satisfying interactive multiobjective thermal power dispatch: SWT approach

In multiobjective optimization, trade-off analysis plays an important role in determining most preferred solution. This paper presents an explicit interactive trade-off analysis based on the surrogate worth trade-off function to determine the best compromised solution. In the multiobjective framework thermal power dispatch problem is undertaken in which four objectives viz. cost, NO_x emission, SO_x emission and CO_x emission are minimized simultaneously. The interactive process is implemented using a weighting method by regulating the relative weights of objectives in systematic manner. Hence the weighting method facilitates to simulate the trade-off relation between the conflicting objectives in non-inferior domain. Exploiting fuzzy decision making theory to access the indifference band, interaction with the decision maker is obtained via surrogate worth trade-off (SWT) functions of the objectives. The surrogate worth trade-off functions are constructed in the functional space and then transformed into the decision space, so the surrogate worth trade-off functions of objectives relate the decision maker’s preferences to non-inferior solutions through optimal weight patterns. The optimal solution of thermal power dispatch problem is obtained by considering real and reactive power losses. Decoupled load flow analysis is performed to find the transmission losses. The validity of the proposed method is demonstrated on 11-bus, 17-lines IEEE system, comprising of three generators. Lakhwinder Singh is Assistant Professor at Baba Banda Singh Bahadur Engineering College, Fatehgarh Sahib. He obtained his B.E. (Electrical) (1990) from Guru Nanak Dev Engineering College, Ludhiana and M.E. (Power Systems) (1995) from Punjab University, Chandigarh. He is currently pursuing Ph.D. from Punjab Technical University, Jallandhar. He is a life member of the Indian Society for Technical Education, and a member of the Institution of Engineers (India). He has published 14 papers in national and international conferences/ journals. His research interests include neural networks, fuzzy logic, power system analysis and optimization. J.S.Dhillon is Professor, Electrical and Instrumentation Engineering Department, Sant Longowal Institute of Engineering and Technology, Longowal (Sangrur). Previously, he had been Assistant Professor (1992–2002) at Giani Jail Singh College of Engineering and Technology, Bathinda, and Lecturer (1987–1992) at Thaper Institute of Engineering and Technology, Patiala. He received his B.E. (Electrical) (1983) from Guru Nanak Dev Engineering College, Ludhiana, M.E.(Systems) (1987), Punjab Agricultural University, Ludhiana, Ph.D., (1996) Thapar Institute of Engineering & Technology, Patiala. He has published/presented more than 63 papers in national and international journals/ conferences. His research interests include power system operation, optimization, genetic algorithm, neural networks and co-authored two books “Power System Optimization”, P.H.I. and “Basic Electrical & Electronics Engineering”, Kalyani Publishers.