International Journal of Smart Electrical Engineering
Volume:5 Issue: 1, Winter 2016

Brain-Computer interface systems are a new mode of communication which provides a new path between brain and its surrounding by processing EEG signals measured in different mental states.  Therefore, choosing suitable features is demanded for a good BCI communication. In this regard, one of the points to be considered is feature vector dimensionality. We present a method of feature reduction using genetic algorithm as a wide search method and we choose 6 best frequency band powers of EEG, in order to speed up processing and meanwhile avoid classifier over fitting. As a result a vector of power spectrum of EEG frequency bands (alpha, beta, gamma, delta & theta) was found that reduces the dimension while giving almost the same correct classification rate.

As there is a rapid growth both in the number of power consumers and also the limitations energy resources, it is clearly accepted that the old version of power grid must change into smart grid from head to toe. One of the most important advantages of smart grid which makes it much more exclusive rather than other typical systems is the two-way connectivity between the utility and the costumers. Taking energy efficiency programs for domestic consumers which are considered with the most important role in raising the rate of energy consumption of all, is accepted as an applicable techniques of demand-side management. In this thesis an identical frequency method control of the electrical motor of an air-conditioner (AC) system based on Fuzzy-PID controller is proposed in order to maximizing energy efficiency. Referring to the statistics which are published about the rate of energy consumption of AC systems would have the highest role in demand response and the two-way cooperation between the utility and costumers. To evaluate the results much more applicable, the proposed method is simulated with MATLAB software and the results have shown that the system have the great success.

This paper proposes per unit coding for combined economic emission load dispatch problem. In the proposed coding, it is possible to apply the percent effects of elements in any number and with high accuracy in objective function. In the proposed per unit coding, each function is transformed into per unit form based on its own maximum value and has a value from 0 to 1. In this paper, particle swarm optimization is used for solving economic emission load dispatch problem. In order to show the advantages of the proposed method, 25 independent case studies are conducted on systems holding three and six power units with different influence percentages of each function are investigated. The obtained results are compared with those of other methods such as Biogeography Based Optimization, Tabu Search, NSGA-II and etc. The obtained results properly show the superiority of the proposed method to combine economic emission dispatch problem over the penalty factor technique and other conventional combined approaches.

A novel low noise trans-impedance amplifier is proposed using low cost 0.18 µm CMOS technology. A resistive-capacitive feedback is used to extend the bandwidth of the amplifier. As the structure is inductor less, it is suitable for low cost integrated optical interconnects. In this paper Improved Particle Swarm Optimization have applied to determine optimal trans-resistance and noise of proposed structure of amplifier. Simulation results showed a -3 dB bandwidth of 5 GHZ with a trans-impedance gain of ≈ 62 dB ohms. The total voltage source power dissipation is less than 5 mW that is much less than that of conventional trans-impedances. The output noise voltage spectral density is 9.5 nV/sqrt(Hz) with a peak of 15nV/sqrt(Hz), while, the input referred noise current spectral density is below 10pA/sqrt(Hz) within the amplifier frequency band.

This study proposes a combination of a fuzzy sliding mode controller (FSMC) with integral-proportion-Derivative switching surface based superconducting magnetic energy storage (SMES) and PID tuned by a multi-objective optimization algorithm to solve the load frequency control in power systems. The goal of design is to improve the dynamic response of power systems after load demand changes. In the proposed method, an adaptive fuzzy controller is utilized to mimic a feedback linearization control law. To compensate the compensation error between the feedback linearization and adaptive fuzzy controller, a hitting controller is developed. The Lyapunov stability theory is used to obtain an adaption law so that the closed-loop system stability can be guaranteed. The optimal PID controller problem is formulated into a multi-objective optimization problem. A Pareto set of global optimal solutions to the given multi-objective optimization problem is generated by a genetic algorithm (GA)-based solution technique. The best compromise solution from the generated Pareto solution set is selected by using a fuzzy-based membership value assignment method. Simulations are presented and compared with conventional PID controller and another new controller. These results demonstrate that the proposed controller confirms better disturbance rejection, keeps the control quality in the wider operating range, reduces the frequency’s transient response avoiding the overshoot and is more robust to uncertainties in the system.

This with the integration of distributed generation (DG) to meshed distribution systems, the operating time of the protective system becomes a major concern in order to avoid nuisance DG tripping. This paper proposes a new tripping characteristic for directional overcurrent relays (DOCRs) that can achieve a higher possible reduction of overall relays operating time in meshed distribution networks tripping. The proposed tripping characteristic is described in detail. The proposed characteristic is tested on the distribution system is a part of a distribution network, owned by Himmerlands Elforsyning, in Aalborg, Denmark. Also, in this paper using hybrid algorithm GA and LP for solve relay coordination problem. Also, in this paper fault considered is kind of three phase fault. Finally, the results of the proposed characteristic compared with a standard IEC characteristic. The result shown that propose characteristic are better than standard IEC characteristic. Therefore, we can use this characteristic for DOCRs.

Wireless sensor networks(WSN) have unique properties that distinguished them from other wireless networks and have special challenges. Not-chargeable, not-changeable and limited power supplies of sensor nodes is the most important challenge of this networks, and if the power supply of node expired, a part of data maybe lost. Because of the importance of covers in wireless sensors, in this work we have presented approaches that in their designs nodes are in special and different areas so that the hole of environment be covered and for saving power consumption, in each active period only one node is active and others are in inactive. For implementing the task cycle and avoiding from over-load of one node, the active node which have the task of sensing and maintaining the cover of area, in the next period, another node will replace it. It seems that by zoning the environment and cycle of tasks, the overall cover of wireless network improves.

This paper works on the concept of flatness and its practical application for the design of an optimal transient controller in a synchronous machine. The feedback linearization scheme of interest requires the generation of a flat output from which the feedback control law can easily be designed. Thus the computation of the flat output for reduced order model of the synchronous machine with simplified turbine dynamics is hereby presented. The corresponding linearized compensator is derived as well as the nonlinear controller for transient stabilization of a synchronous machine subjected to large disturbances.  The transient  behavior  of  a  single  machine equipped  with  the so designed  nonlinear controllers feeding an  infinite  bus  is illustrated  via  simulation  in  Matlab  environment. The results obtained for  transient disturbances on  the  single  machine infinite  bus  system  (SMIBS)  are  presented  and compared with other  control algorithms to demonstrate the effectiveness of the proposed scheme.