Sharif Digital Repository

Deregulation of power system has introduced new objectives and requirements for transmission expansion problem. In this paper, a static transmission expansion methodology is presented using a multi-objective optimization framework. Investment cost, reliability (both adequacy and security), and congestion cost are considered in the optimization as three objectives. To overcome the difficulties in solving the nonconvex and mixed integer nature of the optimization problems, the genetic based NSGA II algorithm is used followed by a fuzzy decision making analysis to obtain the final optimal solution. The planning methodology has been demonstrated on the IEEE 24-bus test system to show the... 

A great deal of computational power and time is necessary for the simulation of highly heterogeneous fractured reservoirs with complicated geometry. Simulating such largescale complex reservoirs with both minimum time and maximum accuracy has consistently remained a topic of concern to reservoir simulation engineers worldwide. The currently used linear solvers in well-known commercial simulators that utilize classical methods such as Nested Factorization (NF) and Incomplete LU Factorization (ILU) as their preconditioners, all suffer from severe convergence problems in models with high heterogeneity and/or large number of non-neighbor connections. To overcome such problems, a novel Adaptive... 

Under smart grid environment, islanding detection plays an important role in reliable operation of distributed generation (DG) units. In this paper an intelligent-based islanding detection algorithm for PV and DFIG units is proposed. Decision tree algorithm is used to classify islanding detection instances. This algorithm is rapid, simple, intelligible and easy to interpret. The error rate of this method is reduced by Adaptive Boosting (AdaBoost) technique. The proposed method is tested on a distribution system including PV, DFIG and synchronous generator. Probable events in the system are simulated under diverse operating states to generate classification data set. First and second order... 

Applying upscaling techniques is an undeniable demand in reservoir simulation, considering the difference between level of details in a geological model and level of details that can be handled by reservoir simulators. Upscaling reservoir model involves first constructing a coarse grid by employing gridding algorithms and then computing average properties for coarse grid blocks. Although various techniques have been proposed for each of these steps, one has to be aware of strengths and weaknesses of each technique before attempting to apply them. In this paper, we focus on different gridding methods and evaluate their performances. Three main grid generation techniques are considered:...