Large wind energy power plants are widely commercialized and integrated in existing electric power grids. The randomness of wind speed over a short period can greatly affect short term generation scheduling. This paper addresses this problem through an optimized day ahead short-term generation scheduling of both thermal and hydrothermal energy systems at different power penetration levels. There are two models of the wind energy power plant are presented and integrated into the developed optimization model. The first model assume priority wind power dispatch in which all wind power is committed regardless the other power plants in the study system. The second model assumes a fixed rate wind power cost. The optimal scheduling problem is solved efficiently using particle swarm optimizer. Various physical and operational constraints are included. The results shows that wind power variation is strongly affect both thermal and hydro power plants generation scheduling especially when priority dispatch criteria is assumed.

This paper presents a new aspect in assessment of Locational Marginal Prices (LMP). LMP values are practically the key indications for handling the settlement procedures in the competitive electricity markets, Therefore the fairness and accuracy of LMP's values have always been the central issues. An approach can be developed, where reactive power costs take part into the objective function of the system dispatch. The intent is to find what happens if the costs of active and reactive powers are explicitly bided and therefore minimized. It is demonstrated the cost of system dispatch will be minimized when the cost of active and reactive power minimized. Unlike traditional way at which the cost of real power only minimized, the LMP values are calculated with respect to both active and reactive cost minimization. Nevertheless, this approach introduces better and cheaper way to deal with system dispatch and its settlement procedures. Importantly, this work illustrates that adding reactive power costs in the objective function of the system affects the LMPs drastically. An IEEE-14 bus system is taken to represent the promised approach.

Voltage instability is major cause of cascading failures in the current power systems. Static assessment of voltage stability has been used widely to draw the secure margin of voltage security for the system components. Among the many methods reported, Conventional Newton Raphson method is popular but it suffers from curse of singularity on its Jacobian matrix which precludes converging onto the solution. To overcome this problem, Continuation Power Flow (CPF) method was come up. CPF method is a very powerful method that can give the solution without having the singularity problem. The CPF method has then been improved using new CPF-GMRES method. In contrary, NRS (Newton - Raphson - Seydel) is old method but is fast and accurate. This paper expands existing NRS method which then demonstrated that it is more reliable and faster than CPF-GMRES and NRS. The algorithm tested on practical 350 bus network in IRAN (Khorasan region).

This paper suggests an exact approach to deal with static assessment of Available Transfer Capability (ATC). It caters an expanded Newton Raphson-seydel (NRS) to see the problem from different point of view. Conventional Newton Raphson (NR) method has the singularity problem over its Jacobian matrix and thus could fail to get the solution. Continuation Power Flow (CPF) method is a very powerful method that can get the solution without having the singularity problem. The CPF method is improved here using the new CPF-GMRES method. NRS commonly recognize as an old method but it is fast and accurate. All in all, the expanded NRS method is reliable and faster than CPF-GMRES and even NRS. The proposed approach is demonstrated on practical 350 bus network in IRAN (Khorasan region).

This paper proposes a new method for solving economic dispatch problems in electrical power systems through the application of multithread programming. Multi-Thread Interior Point Barrier Algorithm, an efficient quadratic programming algorithm, is used to solve economic dispatch problem. The barrier algorithm also caters for any combination of polynomial functions such as polynomial cost functions. Nonlinear characteristics of electrical power system such as generators limitations, transmission losses and nonlinear cost functions are considered in the economic dispatch formulation. Exact transmission loss formula is used in the equality constraint in the economic dispatch equations. The transmission loss coefficients are calculated by using a multi-thread programming. To ensure the optimal dispatch satisfies the line flow limits, line flow constraints has been added to formulation as a security constraint. This optimization problem enable us to solve economic dispatch problems faster, so it is suitable for unit commitment problems and the other power system problems which need to get reasonable speed. IEEE 30, 57, 118 bus case studies are presented and tested with the proposed method.