WEBREVIEW
Accueil > Science et Technologie > Journal of Electrical Systems > Volume 11 > Volume 11

Volume 11

Articles de cette rubrique


A New Space Vector Modulation(SVM) with Optimal Switching Sequence

The need for control algorithm of low switching losses and harmonic distortion is becoming more and more urgent, especially when the high frequency devices are used in the power electronic systems . So a new space vector modulation (SVM) was introduced, which has the virtue of low switching losses and harmonic distortion. And the algorithm model was built to study its operation in Simulink. Simulation results, including the output voltage waveforms and the spectrum of the output line-to-line voltage, were given under various modulation indices and N (the ratio of carrier frequency to modulation wave frequency). The experiments of the algorithm had been carried out based on TMS320F2812 DSP. It is shown that the proposed SVM makes doubled calculations at specified switching frequency. And the output THD of it is better than that of 7-segment SVM.



Enhancement of hybrid dynamic performance using ANFIS for fast varying solar radiation and fuzzy logic controller in high speeds wind

In this paper, dynamic performance enhancement of grid connected hybrid system consists of wind turbine using PMSG and photovoltaic systems are investigated under different circumstances. In order to maximize the output of solar arrays, maximum power point tracking (MPPT) technique is used by an adaptive neuro-fuzzy inference system (ANFIS) and also control of turbine output power in high speeds wind using pitch angle control technic by fuzzy logic are proposed. For tracking the maximum point, the proposed ANFIS is trained by optimum values. The simulation results show that the ANFIS controller of grid-connected mode can easily meet the load demand and have less fluctuation around the maximum power point (MPP), also it can increase convergence speed to achieve MPP. Also pitch angle controller based on fuzzy logic with inputs such as wind speed and active power can have faster responses which lead us to have flatter power curves, enhance the dynamic performance of wind turbine and prevent the both frazzle and mechanical damages to PMSG. The thorough wind power generation system, PV system and power electronic converter interface by using Matlab/Simulink are proposed.



A High Performance Direct Torque Control of PMBLDC Motor using AI

This paper deals with the direct torque control (DTC) of PMBLDC motor using Artificial Intelligence (AI) to improve the performance of the DTC scheme. Though the conventional controllers are commonly used in practice, they have failed to perform satisfactorily under nonlinear conditions and parameter variations. In the proposed work, an AI based control scheme is introduced to control the torque and the flux linkage angle of the DTC scheme. Torque error and flux linkage angle of the DTC scheme are fuzzified and it is auto tuned by GA to improve the dynamic characteristic. Simulation results of the conventional control scheme are compared with the AI based control scheme and the later is found to be satisfactory with
improved performance.



Robust H Tracking Control Combined with Optimized PSS by PSO Algorithm

In this paper, the proposed controller design is based on Htracking control combined with the optimized Power System Stabilizer (PSS). In addition the parameters of the PSS controller are optimized using the Particle Swarm Optimization algorithm (PSO). The aim of this study is to obtain a high performance for the speed deviation and the angle rotor simultaneously, also the damping of the oscillations and the enhancing power system stability. Using the Htracking control show the convergence of the errors to the neighborhood of zero. In order to test the effectiveness of the proposed method, the simulation results clearly indicate the damping of the oscillations of the angle rotor and
angular speed with reduced overshoots which confirms the performance of the
proposed scheme.



Hysteresis Motor Using Heat Treated Fe-Cr-Ni-Mo-C Steel Alloy

Hysteresis motors are exciter less synchronous machines, which have found wide applications in sub fractional horse power ratings. These motors have some favorite features such as constant torque, low startup current and noiseless operation. However, low efficiency and low power factor are common deficiencies of the hysteresis motors, which should be rectified using more suitable rotor substance and having accuracy in design considerations as possible. In general, magnetic property of the rotor material has the most important and plays a key role in the hysteresis motors performance. In this paper, electromagnetic characteristics of a steel alloy which contains iron, chrome, nickel, molybdenum, and carbon (Fe-Cr-Ni-Mo-C) are presented and application of this steel alloy for rotor of hysteresis motors is investigated. Magnetic properties of Fe-Cr-Ni-Mo-C are compared with other common magnetic materials, used in the conventional hysteresis motors. The results confirm eligibility of Fe-Cr-Ni-Mo-C rather than
others



Increasing the Loadability of Power System through Optimal Placement of GUPFC using UDTPSO

This paper concentrates on increasing the loadability of power system. The most powerful multi-line FACTS controller, Generalized Unified Power Flow Controller (GUPFC) is considered using power injection model. While finding the optimal installation location for GUPFC, transmission line thermal limits and bus voltage limits are taken into consideration. The overall system and area wise loadability is enhanced in the resence of GUPFC with static and dynamic loads under normal and contingency conditions. A novel optimization algorithm based on uniform distribution of control variables and two-stage initialization processes included
in conventional Particle Swarm Optimization (PSO) to start the convergence of problem with good initial value and reaches best final value in less number of iterations. The proposed methodology is tested on standard IEEE-30 bus test system and the obtained results are quite encouraging and will be useful for power system restructuring.



Design and FE Analysis of BLDC Motor for Electro- Mechanical Actuator

This paper presents the design of Surface Mounted BLDC Motor for Electro-mechanical actuator. The Electro-mechanical actuators are extensively used in aerospace and defence industry. The preferred motor for such applications is BLDC motor as it is compact in size, offers high speed operation and has high orque to inertia ratio, high efficiency etc. Motor is designed analytically to meet the given specifications of the actuator. The designed motor is verified by conducting Finite Element Analysis (FEA) on the dimensions obtained through analytical calculations. The FEA is conducted on no load and on loaded condition of the motor. The armature reaction effects mainly demagnetizing and cross magnetizing effects on the permanent magnet are analyzed. Finally non-linear FEA concludes that flux, flux density and magnetizing force etc. in various parts of the motor are in the specified limits and motor meets the desired specifications.



Soft computing technique based reactive power planning using NVSI

This paper proposed an application of New Voltage Stability Index(NVSI) to Reactive Power
Planning(RPP) using Soft Computing Technique based Differential Evolution(DE).NVSI is used
to identify the weak buses for the Reactive Power Planning problem which involves process of experimental by voltage stability analysis based on the load variation. The Formulation of a New Voltage Stabilty Index(NVSI),which is originates from the equation of a two bus network,neglecting the resistance of transmission line,resulting in appreciable variations in both real and reactive loading.The proposed approach has been used in the IEEE 30-bus system.Results show considerable reduction in system losses and improvement of voltage stability with the use of New Fast Voltage Stability Index for the Reactive Power Planning problem.



Discrete-Time Integral Variable Structure Control of Grid-Connected PV Inverter

In the paper a new discrete-time integral variable structure control of grid-connected PV inverter is proposed in order to maximize the input power given by PV arrays and at the same time for using the grid-inverter as a reactive power compensator. In the last years different variable structure controls (VSC) have been proposed in literature. In spite these algorithms have been implemented on digital hardware, they have been developed by means of a timecontinuous formulation neglecting the effects of a microprocessor-based implementation. Such approach can cause an increasing amplitude chatter of the state trajectories which means instability. The proposed VSC is fully formulated in discrete-time, taking into account the effects introduced by a microprocessor-based implementation. Moreover it introduces respect to the classical formalization of the VSC an integral action that improve the performance of the controlled system. After a detailed formalization of the proposed control algorithm, several numerical and experimental results on a three-phase grid-connected inverter prototype are shown, proving the effectiveness of the control strategy. Thanks to the proposed control law the controlled system exhibits fast dynamic response, strong robustness for modelling error and good current harmonic rejection.



Solar Charger Sizing

As a part of the optimization of photovoltaic energy extraction, an optimization of each individual component is required. This paper focuses on the optimization of solar attery charger block and presents a new method to track the maximum power point and the load regulation. For this purpose, we proposed a specific architecture and design of a high-reliable, robust, stable, miniaturized system. We sized a photovoltaic charger to regulate the battery charger that employs an intelligent algorithm including the criteria of reliability.



| info visites 2128185

Suivre la vie du site fr  Suivre la vie du site Science et Technologie  Suivre la vie du site Journal of Electrical Systems  Suivre la vie du site Volume 11   ?

Creative Commons License