Sharif Digital Repository

As a matter of fact, power systems are always faced with a variety of uncertainties. These uncertainties change system parameters in an unwanted manner which may deteriorate the system security and reliability. For instance, a transmission line which is designed for a certain capacity may be suffered as a result of load increment and consequently may influence the normal operation of other network elements. In recent years, as a result of environmental considerations and especially after the oil shock at 1973 which caused the the energy prices to increase unprecedentedly, the human has taken more attention to renewable energies exploitation. Theses energies have a fluctuating nature and are... 

This thesis presents a variety of methods have been proposed for optimal locating and sizing of Distributed Resource (DR) in restructured power system to reduce congestion and enhance security. Initially three different methodologies, based upon LMP and congestion rent, are presented that form priority list of candidate buses to reduce solution space. For taking into account security, The N−1 contingency criterion is performed and then a priority list of the worst contingencies from congestion rent point of view is organized. Based upon both normal condition and selected contingencies of the network a priority list of buses for optimal placement and for each level of power output of DR is... 

The competition between producers and the contracts issues between the producers and consumers of electrical energy in restructured power systems might cause on unwanted increase in power interchange beyond transmission lines capacity. If the power interchange is not well-managed, it would often cause overloads in specific path. This phenomenon is termed as lines congestion. The major goal of congestion management is to create a set of rules that ensure sufficient control over producers and consumers to maintain an acceptable level of power system security and reliability in the time of limitation of transmission network with maximizing economic market efficiency. As FACTS devices provide... 

Regarding increasing rate of electrical energy demand, paucity of fossil fuels and the pollution stemmed from burning them, using renewable energy is inevitable. For transmitting the generated electrical energy to grid, power electronics converters are used. Inverters and back-to-back converters are some of these converters. Inverters and back-to-back converters are used in connecting photovoltaic power plants and wind systems to grid respectively. Because of technological limitation, converters are paralleled with others at high power transmitting. Paralleling converters has other merits such as increasing system reliability through redundancy and repairing defective converter without...