JOURNAL OF ELECTRICAL ENGINEERING DEPARTMENT, TRANSACTION ON ELECTRICAL TECHNOLOGY (ELECTRONICS AND POWER)
Year:2010 | Volume:2 | Issue:2|Papers Count:9

In this paper, a nonlinear loss minimization control strategy for an interior permanent magnet synchronous motor (IPMSM) based on a newly developed sliding mode approach is presented. This control method sets force the speed control of the IPMSM drives and simultaneously ensures the minimization of the losses besides the uncertainties exist in the system such as parameter variations which have undesirable effects on the controller performance except at near nominal conditions. Simulation results are presented to show the effectiveness of the proposed controller.

One of the benefit of FACTS devices is increase of stability in power systems with control active and reactive power at during the fault in power system. Although, the power system stabilizers (PSSs) have been one of the most common controls used to damp out oscillations, this device may not produce enough damping especially to inter-area mode and therefore, there is an increasing interest in using FACTS devices to aid in damping of these oscillations. In This paper, UPFC is used for damping oscillations and to enhance the transient stability performance of power systems. The controller parameters are designed using an efficient version of the Takagi-Sugeno fuzzy control scheme. The function based Takagi-Sugeno-Kang (TSK) fuzzy controller uses. For optimization parameters of fuzzy PI controller, the GA, PSO and HGAPSO algorithms are used. The computer simulation results, the effect of UPFC with conventional PI controller, fuzzy PI controller and intelligent controllers (GA, PSO and HGAPSO) for damping the local-mode and inter-area mode of under large and small disturbances in the four-machine two-area power system evaluated and compared.

This paper presents a new method for designing of power system stabilizer (PSS) based on sliding mode control (SMC) technique. The control objective is to enhance stability and improve the dynamic response of the multi-machine power system. The mathematical model of the synchronous generator is first transformed into a form that facilitates the design of nonlinear control schemes. Then, a sliding mode controller is proposed. In order to test effectiveness of the proposed scheme, simulation will be carried out to analyze the small signal stability characteristics of the system about the steady state operating condition following the change in the parameters of the system and to the disturbances. For comparison, simulation of a conventional control PSS (lead-lag compensation type) will be carried out. The main approach is to focus on the control performance which later is proven to have the degree of shorter reaching time and lower spike.

High voltage insulators are exposed to different ambient and climate conditions the interactions of ambient condition and insulator contamination led the insulators themselves become a proper medium for conduction of current, leaving their effects on the power system. Presently, approximate and empirical numbers are used to determine the level of contamination of the insulation. As a result, creep internals in some area do not accord to ambient conditions and are below the design level. In this power by periodic ESDD and NSDD measurements, two method direction dust gauge DGG are used to measure the intensity of the ambient pollution on the insulator and OLCA to display and record the leaking current as appropriate criteria for the degree and type of pollution.

In this paper, we introduce quantum fourier transform as a key ingredient for many useful algorithms. These algorithms make a solution for problems which is considered to be intractable problems on a classical computer. Quantum Fourier transform is propounded as a key for quantum phase estimation algorithm.In this paper our aim is the implementation of period-finding algorithm.Quantum computer solves this problem, exponentially faster than classical one. Quantum phase estimation algorithm is the key for the period-finding problem .Therefore, by means of simulating quantum Fourier transform, we are able to implement the period-finding algorithm.In this paper, the simulation of quantum Fourier transform is carried out by Matlab software.

Numerous methods have been developed to solve the path planning problem, among which the visibility graph, Voronoi diagram, Quad-Tree and Wave-Front are well-known techniques. In this paper, a new global path planning algorithm named HYBRID-Visibility-QuadTree-Voronoi-WaveFront method (HYBRID-VQVW) is presented where these four methods are integrated in a single architecture. After constructing these global trajectories of C-space, the best trajectory among four is selected in every sampling distance by several criterions. These criterions consist of length, smoothness and safety of the trajectory. In fact, the algorithm provides a parametric tradeoff between shortest, safest and smoothest paths and generally yields shorter and smoother paths than the Voronoi, Quad-Tree and Wave- Front methods, and safer than the visibility graph.

In this paper, a new isolated dc-dc bidirectional converter is proposed. This converter consists of two transformers (flyback and forward) and only one switch in primary side and one switch in secondary side of transformers. In this converter energy transfers to the output in both on and off switch states so power density of this converter is high This converter controlled by PWM signal. Also this converter operates over a wide input voltage range. Theoretical analysis is presented and computer simulation and experimental results verify the converter analysis.

This paper presents the mathematical analysis and modeling of a 4th order LCLC resonant converter with capacitive output filter in steady-state condition. Due to the nonlinearity of the LCLC resonant circuit with capacitive output filter, the conventional modeling procedure cannot thoroughly describe the behavior of the converter. In this paper, a mathematical model is proposed that can accommodate the absence of the output inductor and predict the converter performance for a wide range of operating conditions. A 2.25KW prototype converter is provided to evaluate the accuracy of the proposed model. Experimental results show that the proposed model can precisely predict the behavior of the converter for a wide range of operating conditions.