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Preventive control based on complex-valued load-flow technique to avoid voltage instability in power systems |
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| Authors: | Naoki Kameoka Hiroyuki Kita Eiichi Tanaka Jun Hasegawa Ken-Ichi Nishiya |
| Affiliation: | 1. Tohoku Electric Power Co Naoki Kameoka received his M.E. degree in 1993 from Hokkaido University. He has been with the Tohoku Electric Power Co. since April of the same year. He was engaged mainly in research on control of power systems while in school.;2. Hokkaido University Hiroyuki Kita received his M.E. degree from Hokkaido University in 1988 and entered the doctoral program in April of the same year. Since April of 1989 he has been a Research Associate in the Department of Electrical Engineering, Hokkaido University. He is engaged mainly in research on analysis and control of power systems.;3. Hokkaido University Eiichi Tanaka received his M.E. degree from Hokkaido University in 1977. Since April of the same year he has been a Research Associate in the Department of Electrical Engineering, Hokkaido University. He is engaged mainly in research on analysis and control of power systems. He is a member of the Society of Instrument and Control Engineers.;4. Hokkaido University Ken-ichi Nishiya received his B.S. and Ph.D. degrees from Hokkaido University in 1969 and 1983, respectively. He was a Research Associate in 1969 and later an Associate Professor at Hokkaido University, and in 1991, a Professor at Hokkaido Institute of Technology. He is engaged in research on power systems engineering, particularly in state estimation, analysis as well as operation and planning of power systems. He is a member of the Institute of Systems, Control and Information Engineers.;5. Hokkaido Institute of Technology Jun Hasegawa received his Dr. of Eng. degree in 1971 from Hokkaido University. He was a Lecturer and an Associate Professor at Hokkaido University and has been a Professor there since April 1985. He is engaged mainly in research on the planning, operation, control and analysis of power systems as well as the energy storage. He is a member of the Operations Research Society of Japan, and the IEEE. |
| Abstract: | This paper presents a method for obtaining preventive control strategies based on nonlinear optimization for power systems which will incur voltage instability when load demand increases. An algorithm is proposed to determine an appropriate and effective control action taking into account the operating constraints to widen the margin between the present operating point and a voltage collapse point, thereby improving the system state. The method proposed here is based on a complex-valued load-flow technique using the Newton-Raphson method which has been developed already by the authors. Consequently, the preventive control algorithm also can evaluate the voltage instability in the event the present operating point becomes closer to the critical point and the system state becomes unfeasible at increased loading point. Further, in optimization, two-types of objective functions are introduced so that voltage stabilization and dissolution of constraint violation can be attained simultaneously. In addition, this paper discusses the extension of the proposed preventive control to the successive control method which carries out the control action to avoid voltage collapse while the load demand is increasing. Numerical examples for various model systems demonstrate the effectiveness of the proposed method. |
| Keywords: | Power system voltage stability complex-valued load-flow calculation preventive control avoidance control nonlinear optimization |