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The cuckoo search (CS) algorithm is a simple and effective global optimization algorithm. It has been successfully applied to solve a wide range of real- world optimization problem. In this paper, a modified CS algorithm is applied to determine the feasible optimal solution of the economic load dispatch problem considering various generator constraints. In order to solve the problem of being trapped into the local optima, a new mutation scheme, inspired by the DE/current-to-gr_best/1, is incorporated in standard CS to enrich the searching behavior and solution quality and to avoid being trapped into local optimum. In order to verify the performance of our approach, the proposed approach is tested with two power system cases consisting of 3, 6, 15, and 40 thermal units with generator constraints. State-of-the-art optimization techniques are compared with simulation results obtaining proposed method to illustrate the efficiency of the proposed method and to show that the improved CS could be used as a reliable tool for solving economic load dispatch problems with generator constraints. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper presents an effective technique for tracking and finding the direction of switched capacitor banks in distribution system generating switching transient when certain number of power quality meters exist. The proposed method is comprised of two independent algorithms. Algorithm utilizing the steady-state power quality data based on changes of the phase-angle difference between voltage and current and algorithm utilizing the transient state power quality data based on branch voltage and current changes immediately before and after the capacitor switching instant. This technique uses modal current and voltage signals that can be constructed by combining three-phase current and three-phase voltage. Wavelet transform is used to detect the exact instant of switching transient. The efficiency of proposed method was validated using IEEE 34-bus distribution system, modeled in PSCAD. [ABSTRACT FROM AUTHOR]

The practical aspects of constructing an ironless axial flux direct-drive generator for Mind applications are presented in this paper. In other words, the design procedure for this 50 kW-generator is discussed in details as well as the construction procedure. This generator provides various advantages which are distinctly discussed in this work In this structure, both rotor and stator are designed without any ferromagnetic materials. Because of the absence of ferromagnetic materials and gearbox, the total mass of system is less than equivalent designs based on iron-cored magnetic circuits. The genetic algorithm is used to optimize machine structure and to achieve high power density and ejftciency. As a result, the constructed 50kW-generator has been found to have a proper volume as well as an appropriate efficiency. Unlike other generator structures, the iron losses are completely omitted in this structure. This issue contributes to achieve high efficiency. In addition, the armature reaction effect is considerably reduced because of the significant decrease in the synchronous reactance. In this structure, like slotless machines, there Is no cogging torque. The generator operation is investigated in both simulation and implementation. The validity of this generator structure is demonstrated by great agreement between simulation and implementation results. [ABSTRACT FROM AUTHOR]

In this paper, a new fuzzy controller for a three-phase and three-wire distribution static compensator (DSTATCOM) is presented to improve power quality. A three-leg voltage source converter based DSTATCOM is used to control the harmonic currents for two nonlinear loads. In this control system, gate pulses for IGBT switches are provided by a hysteresis controller, using samples of source voltages and currents. The derived reference currents, obtained by the direct method of reference current estimation with two PI and Fuzzy control models are simulated in a MATLAB/ Simulink environment and each performance is analyzed. Comparisons show that the fuzzy controller performs better than a classic PI controller. [ABSTRACT FROM AUTHOR]

This paper provides an algorithm of fault resistance compensation for digital ground distance relay considering the voltage and current transformer effects. Performance of the conventional ground distance relaying manner is adversely affected by different ground faults and also typical type, called a simultaneous open conductor and ground fault. The proposed scheme by using local-end data only, has shown satisfactory performances under wide variations in fault location, with different values of fault resistance and having positive and negative of power transfer angle. The presented method which has been carried out on the IEEE 14 bus benchmark is executed in PSCAD/EMTDC and MATLAB software, and the results show the accurate performance of mentioned configuration. [ABSTRACT FROM AUTHOR]

This paper provides an algorithm of fault resistance compensation for digital ground distance relay considering the voltage and current transformer effects. Performance of the conventional ground distance relaying manner is adversely affected by different ground faults and also typical type, called a simultaneous open conductor and ground fault. The proposed scheme by using local-end data only, has shown satisfactory performances under wide variations in fault location, with different values of fault resistance and having positive and negative of power transfer angle. The presented method which has been carried out on the IEEE 14 bus benchmark is executed in PSCAD/EMTDC and MATLAB software, and the results show the accurate performance of mentioned configuration. [ABSTRACT FROM AUTHOR]