الفهرس | Only 14 pages are availabe for public view |
Abstract The Congestion in a transmission grid occurs due to an operating condition that causes limit violations on one or more of the “line flows” in the system. Congestion or overload in one or more transmission lines of the system may occur as a result of unexpected outages of generation, sudden increase of demand, tripping of transmission lines, or failures of other equipments. In deregulated power systems, congestion, which can also occur due to commercial reasons, has become a major concern. Fast, transparent, and effective tools are necessary for congestion management. This thesis presents a proposed optimization technique (POT) for solving the transmission congestion management problem in competitive power systems at normal and emergency conditions. The fuzzy linear programming (FLP) is suggested as an intelligent optimization technique for solving transmission congestion management problem. Two shapes modelling of fuzzy memberships are proposed and compared with the linear programming technique, as a conventional optimization technique. Two objectives are introduced which are: minimizing the costs of power generations and maximizing the profit of power station. However, the profit is the difference between the market revenue and market payment, production cost of power generation units. A multi–objective function for (FLP) is suggested to find the maximum profit for different shapes of fuzzy membership models. Four standard test systems are used to extensive study of the (POT). One of these test system is a real system as a part of Egyptian United Network. Simulation results show that the POT is more accurate and efficient, especially with large scale of power systems. |