Electromechanical Energy Conversion Systems
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Electromechanical Energy Conversion Systemsendaily1Sun, 01 Dec 2019 00:00:00 +0330Sun, 01 Dec 2019 00:00:00 +0330Multiple Robot motion Planning Considering shortest and safest trajectory
http://eecs.nri.ac.ir/article_119125.html
Extending multiple robot motion planning in unknown workspaces is a interesting scope in the Robot motion planning that in this paper is considered. It is used from radiation robots sensors in order to detect their surroundings and positions of the other robots. In this article a new approach considering two objectives is introduced. Finding safest path is as the first objective. The second objective is achieving a trajectory with minimum length. For finding the safest path, it is used from Voronoi Diagram (VD). To provide the safest path, minimizing the distance to the VS is as important criterion. Due to the VD is a geometric location with a distance from all obstacles to the workspace, therefore it is can be a suitable criteria for finding the safest path. For achieving the shortest path as the secondary objective, it is applied Euclidean distance the current position of the robot to goal position. Algorithm that applied for solving this problem is particle swarm optimization (PSO).A Novel Energy Storage System Usage Based on Ultra-capacitor in Variable Speed Wind Turbines (VSWT) for Power Improvement
http://eecs.nri.ac.ir/article_119134.html
Wind power as a renewable energy has the potential to become a clean energy source in almost all countries of the world but, there are lots of technical challenges that need to be addressed in advance. Wind speed variation (WSV) is one of the most important issues. Separate from its mechanical effects on wind turbines (WTs), it causes electrical power variations on WT as well. Doubly Fed Induction Generators (DFIGs) and Maximum Power Point Tracking (MPPT) system have been helpful so far but some problems such as inertia still needed to be solved. Inertia in the WTs causes a delay on MPPT. This paper proposes a novel method to increase WTs output power in which a DFIG equipped with an energy storage system such as Ultra-capacitor helps MPPT system to track the wind variations rapidly by absorption or injection energy during the wind changes. The ultra-capacitor and control system are modeled and simulated in Matlab/Simulink&reg; environment. The simulation results proofs that the proposed system can improve electrical power and increase electrical energy during WSVs. The simulation model will lead to more penetration of wind power and also enables engineers to optimize the system.AN ANALYTICAL PREDICTION FOR MAGNETIC FIELD DISTRIBUTION IN ONE SMPMSM BASED ON SUBDOMAIN MODEL
http://eecs.nri.ac.ir/article_119126.html
The purpose of this paper is to present an Analytical Predict the Electromagnetic Field Density in surface mounted permanent magnet synchronous motors based on a subdomain field model. In this paper, which is one of a series of four, a 2-d analytical method for predicting field distribution in one SMPMSM is presented. In the presented method, Maxwell&rsquo;s equations have been solved in different regions in pseudo-Cartesian coordinates system taking into account the non-homogeneous boundary conditions. The domain of the magnetic field is divided into four subdomains, viz. magnets, air gap, stator core and outer region. The governing equations and the boundary conditions to the interfaces between these subdomains are formulated in polar coordinate. The analytical prediction is validated by corresponding finite-element method. In future articles, we intend to study the effect of eccentricity on the distribution of magnetic fields in all areas of the motor at one slot less permanent magnet motor.Estimation of the dynamic parameters of a battery model under the hysteresis effect employing a hybrid algorithm of particle swarm optimization and grey wolf optimizer
http://eecs.nri.ac.ir/article_119127.html
An accurate estimation of battery model parameters is essential for dynamic simulation of electric vehicles. Generally, parameterizing battery models are difficult and complex. Therefore it requires powerful estimation algorithms to overcome time-consuming and computational costs. In this paper, the dynamic parameters of a battery model were estimated at 8 different temperatures and under the hysteresis effect. The estimation is based on a hybrid algorithm of particle swarm optimization and grey wolf optimizer. By this hybridization the ability of exploitation in particle swarm optimization and the ability of exploration in grey wolf optimizer improved and both variants were empowered. The algorithm was implemented to estimate parameter values by minimizing the error between experimental data and the predicted results to find an optimal solution for an accurate model. Following a comparison with G.Plett&rsquo;s, the results indicated that the proposed algorithm can reach higher precision in the battery behavior because of the lower error possibility.SUSTAINABILITY-ORIENTED SUPPORT MECHANISMS FOR PROMOTION OF RENEWABLE ENERGY SYSTEMS
http://eecs.nri.ac.ir/article_119124.html
Traditionally, power system planning problem focuses on finding the least-cost generation resources including typical conventional fossil fuel based units without paying attention to a complete set of available generation portfolio alternatives. The predominant share of conventional fossil fuel units in power generation sector has increased concerns on climate changes, energy security, and price volatility . Having these challenges in mind, many power systems have started changing their generation portfolio including significant amounts of renewable energy resources toward a sustainable energy development.This paper presents a comprehensive approach for Generation Expansion Planning (GEP) problem in the presence of Distributed Energy Resources (DER). Different support schemes for DER investors are considered and their impacts on sustainable development are modeled. Regarding this matter, several indicators are presented for evaluating different aspects of sustainable development achievements. Moreover, a decision making framework is proposed using a combined fuzzy Analytic Hierarchy Process (AHP) and Technique for Order Performance by Similarity to Ideal Solution (TOPSIS). The effectiveness of the proposed framework is assessed by a numerical study on a test system.A Survey on Permanent Magnet Synchronous Machines: Recent Applications and Trends
http://eecs.nri.ac.ir/article_119133.html
In the PMSM, by creating a sinusoidal distribution for conductors at the stator surface, the airgap&rsquo;s flux density is closer to the sinus form [1]. By replacing the field&rsquo;s winding with a permanent magnet, the brushes, slip-rings, and copper losses could be removed from synchronous motor. The permanent magnet generates motors with permanent excitation. Fig. 1, shows two different ways in which permanent magnets are put into rotor . The following figure shows the ratio of magnetic torque to reluctance torque in synchronous machines. Regarding the mechanism of torque producing, synchronous machines are divided into three distinct groups. The surface-PMSM (SPMSM), in which arc-shaped permanent magnets are embedded on the surface of cylindrical rotor . Such machine is a complete PMSM which produces only magnetic torque. Synchronous reluctance machine (synRM) is a pure reluctance machine shown in Fig. 2. f. The inset SPMSM belongs to SPMSM category in terms of magnet arrangement, however it is a combined reluctance-magnetic motor because of its magnetic saliency. Interior PMSM (IPMSM) in which permanent magnets are buried inside the rotor (Fig. 2. c, d, and e) has magnetic saliency, so it is a hybrid reluctance-magnetic motor which can be considered as a PMSM motor regarding its reluctance torque (region II) or a synRM motor regarding its magnetic torque.