International Journal of Smart Electrical Engineering
Volume:2 Issue: 2, Spring 2013

An approach for assignment of the optimal location and tap changer adjustment related to flux-lock type superconducting fault current limiters with tap changer (TC-FLSFCL) is used in this paper by debating the reduction of fault current flowing from each device and enhancement of reliability varying with customer type in a distribution network connected with distribution generation (DG). TC-FLSFCL is a flexible SFCL that it has some preference than previous SFCLs. In this type of SFCL the current limiting characteristics are improved and the fault current limiting level during a fault period can be adjusted by controlling the current in third winding, which also made the magnetic field apply to the high-Tc superconducting (HTSC) element. Three objective functions based on reliability index, reduction of fault current and number of installed TC-FLSFCL is systematized and non-dominated sorting genetic algorithm-II (NSGA-II) style is then formed in searching for best location and tuning of tap changer of TC-FLSFCL to meet the fitness requirements. A decision-making procedure based on technique for order preference by similarity to ideal solution (TOPSIS) is used for finding best compromise solution from the set of Pareto-solutions obtained through NSGA-II. In a distribution network as Bus 4 of Roy Billinton test system (RBTS), comparative analysis of the results obtained from application of the resistive SFCL (RSFCL) and TC-FLSFCL is presented. The results show that optimal placement of TC-FLSFCL than RSFCL can improve reliability index and fault current reduction index with less number

In this paper, a method for automatic stitching of radiology images based on pixel features has been presented. In this method, according to the smooth texture of radiological images and in order to increase the number of the extracted features after quality enhancement of initial radiology images, 45 degree isotropic mask is applied to each radiology image to observe the image details. After this process, we used statistical and heuristic image noise extraction method (SHINE) to acceptably reduce the noise resulting from radiation of alternating X-rays on detector. Pixel point’s features are obtained by selecting maximum or minimum value of the brightness of pixels in certain neighborhood of the resulting radiology images. This algorithm transmutes point’s features to 128 dimensional vector features. In order to identify the segments overlapping in basic radiology images, we specify equivalent vector features of each radiology image using the mathematical properties of the vectors and find the fit geometry transform between pairs features matched by the random sample consensus (RANSAC) algorithm. Finally, resulted motion model is applied to the initial radiology images and we stitch them together in a common surface

A wind farm is a collection of wind turbines built in an area to provide electricity. Wind power is a renewable energy resource and an alternative to non-renewable fossil fuels. In this paper impact of wind farms in power system reliability is investigate and a new procedure for reliability assessment of wind farms in HL1 level is proposed. In proposed procedure, application of Fuzzy – Markov for wind speed modelling and calculating reliability indices by probabilities of generation units by calculating state transition matrix is proposed. Fuzzy logic for this method will be possible to calculate the reliability in accordance with the existing uncertainties.
Fuzzy-Markov approach is appropriate for wind farms that have insufficient data of wind speed. In this theory, by state transition probability matrix solution can be obtained probabilities of states of fuzzy- Markov model, by solving state- space differential equation. Finally, the authenticity of approach is shown with some simulation

Today, DC motors is still being used globally due to their easy speed controllability. In this article, an Adaptive Neuro-Fuzzy Inference System (ANFIS) controller is designed for DC motors. The main purpose of performing such task is to reduce the DC motor starting current and deleting the ripple current during starting time in considering control parameters such as: rise time, settling time, maximum overshoot and system steady state error. The results have been simulated in MATLAB and a comparison is made between ANFIS controller and PID controller

In this paper, a stochastic two-stage model is offered for optimization of the day-ahead scheduling of the microgrid. System uncertainties including dispatchable distributed generation and energy storage contingencies are considered in the stochastic model. For handling uncertainties, Monte Carlo simulation is employed for generation several scenarios and then a reduction method is used to decrease the number of scenarios. The scenarios are used in second stage of the stochastic model to check the system security. The amount of spinning reserve and energy are optimized in the first stage by minimizing the total cost of operation. A sample microgrid is used to compare the offered stochastic model with the deterministic one

Routing in ad-hoc networks, specifically intelligent-based ones, is a highly interested research topic in recent years. Most of them are simulation-based study. Large percentages have not even mentioned some of the fundamental parameters. This strictly reduces their validity and reliability. On the other hand, there is not a comprehensive framework to classify routing algorithms in wireless sensor networks yet. In this paper, we present a novel comprehensive taxonomy for routing algorithms along with a complete experimental evaluation framework. It makes the ability to put each routing algorithm in its place. It also provides a complete view of the algorithm behavior. At the end, a proper framework is introduced to express essential simulation parameters too. This can lead to improve the quality of scientific practices in the simulation studies.

This paper presents a sensorless system drive on primary flux oriented control (PFOC) and secondary flux oriented control (SFOC) for the linear induction motor (LIM) with taking into account end effect. Extended kalman filter (EKF) is applied to estimate LIM speed by measuring motor voltages and currents. In order to achieve desirable dynamic and robustness motor performance instead of traditional PI controller, a fuzzy PI controller is used for speed regulation in LIM vector control. The accuracy and validity of fuzzy PI controller operation are investigated and evaluated and its results are compared with traditional PI controller. Transient and steady state responses of proposed controller under load thrust variations and speed command are studied. Also characteristics and performances of primary flux oriented control (PFOC) and secondary flux oriented control (SFOC) for the linear induction motor are compared with each other. In order to evaluate the proposed method, simulations are performed in MATLAB/SIMULINK. Results show that the fuzzy PI controller has more excellent performance than the traditional PI controller and also PFOC has better performance than SFOC, because SFOC depend on rotor resistance. EKF properly estimate motor speed by measuring motor voltages and currents and therefore speed sensor can be eliminated

An efficient cluster head selection algorithm in wireless sensor networks is proposed in this paper. The implementation of the proposed algorithm can improve energy which allows the structured representation of a network topology. According to the residual energy, number of the neighbors, and the centrality of each node, the algorithm uses Fuzzy Inference Systems to select cluster head. The algorithm not only balances the energy load of all nodes, but also provides a reliable selection of a new cluster head and optimality routing for the whole networks. Simulation results demonstrate that the proposed algorithm effectively increases the accuracy to select a cluster head and prolongs the network lifetime