Static characteristics of the double rotor switched reluctance motor

Static measurement characteristics of the double rotor switched reluctance motor developed on the basis of double salient dual air-gap structure is put forward in this paper. The reduction of the air - gap length of the conventional machine is constrained by the mechanical intolerances that inherit the torque generating capability. Therefore there is always a limitation on the air-gap length. However, with reduced air-gap length the magnetic flux control is improved with the aid of dual air-gap structure inside the machine. Analytical and finite element analysis is carried out to investigate the magnetic field distribution at different rotor positions and with different currents. The static torque characteristics derived from the fabricated model is compared with that of the finite element methods and analytical methods. The measurement results are in closer agreement with the analytical and simulation. Motor constant square density is used for the performance evaluation of the proposed machine and the characteristics are evaluated and compared by all three methods presented

Sign language gesture recognition with bispectrum features using SVM

Wi-Fi based sensing system captures the signal reflections due to human gestures as Channel State Information (CSI) values in subcarrier level for accurately predicting the fine-grained gestures. The proposed work explores the Higher Order Statistical (HOS) method by deriving bispectram features (BF) from raw signal by adopting a Conditional Informative Feature Extraction (CIFE) technique from information theory to form a subset of informative and best features. Support Vector Machine (SVM) classifier is adopted in the present work for classifying the gesture and to measure the prediction accuracy. The present work is validated on a secondary dataset, SignFi, having data collected from two different environments with varying number of users and sign gestures. SVM reports an overall accuracy of 83.8%, 94.1%, 74.9% and 75.6% in different environments/scenarios.Taylor's University through its TAYLOR'S PhD SCHOLARSHIP Programmeinfo:eu-repo/semantics/publishedVersio

Reduced mechanical oscillations using the MAGLEV concept in vertical axis wind turbine

Due to its low power design applications, the Vertical Axis Wind Turbine is more commonly employed for the standalone applications. The power generating capability in wind turbines is influenced by the mechanical dimensions of the blade including the shape of the blade and the angle of attack. The appropriate design of the blade shape and position tends to improvise the efficiency even at low wind speed. Initially the shape of the airfoil is designed and analyses and the position for a five blade structure is investigated. The degree of impact at angle of 30° is found to have the highest lift coefficient for the chosen airfoil structure. The use of MAGLEV concept in the VAWT reduces the vibration by 37.5%. Experimental results are presented with and without MAGLEV imported to the VAWT design. Also it is measured that the power generated with maglev system is increase by 12 % compare to the normal wind turbine

MITIGATION OF POWER QUALITY ISSUES IN DISTRIBUTION SYSTEMS USING HARMONIC FILTERS AND CAPACITOR BANKS

Due to increased load demand, the power system developers are encouraged to meet power quality requirements. Using harmonic filter and capacitor bank is one of the essential solutions in mitigating power quality issues. This research aims to mitigate harmonics and improve the voltage in distribution systems by using ETAP. For this purpose, a distribution system in Homs city is considered, which is a part of Syrian power system. The capacitor banks are designed using numerical analysis and Optimal Capacitor Placement (OCP). The results indicate that this approach enhances the voltage profile, which is reflected in some buses. The voltage profile is effectively improved on several buses, and power losses are significantly reduced. The Total Harmonic Distortions (THDs) and Individual Harmonic Distortions (IHDs) of the subjected buses are reduced. Moreover, the power factor is improved from 0.877 to 0.926 for the studied system

Voltage Oriented Controller based Vienna Rectifier for Electric Vehicle Charging Stations

Vienna rectifiers have gained popularity in recent years for AC to DC power conversion for many industrial applications such as welding power supplies, data centers, telecommunication power sources, aircraft systems, and electric vehicle charging stations. The advantages of this converter are low total harmonic distortion (THD), high power density, and high efficiency. Due to the inherent current control loop in the voltage-oriented control strategy proposed in this paper, good steady-state performance and fast transient response can be ensured. The proposed voltage-oriented control of the Vienna rectifier with a PI controller (VOC-VR) has been simulated using MATLAB/Simulink. The simulations indicate that the input current THD of the proposed VOC-VR system was below 3.27% for 650V and 90A output, which is less than 5% to satisfy the IEEE-519 standard. Experimental results from a scaled-down prototype showed that the THD remains below 5% for a wide range of input voltage, output voltage, and loading conditions (up to 2 kW). The results prove that the proposed rectifier system can be applied for high power applications such as DC fast-charging stations and welding power sources

Mathematical toolbox and its application in the development of laboratory scale vertical axis wind turbine

Wind turbine works with the principle of extracting energy from the wind to generate electricity. The power generated is directly proportional to the wind speed available. There are two major types of wind turbine design, namely the horizontal and vertical axis wind turbine depending on the orientation of the turbine rotor and its generator. This paper deals with the design of vertical turbine due to its advantage of operating at a low wind speed over that of horizontal turbine. The analysis of change in the parameters of a vertical axis wind turbine is investigated to get the optimized way in which the rotor of the turbine is to be designed. This is done through modelling and simulation of the turbine using various parameters in the MATLAB/SIMULINK environment. A graphical user interface is created for a generic model of vertical axis wind turbine that is used to determine its parameters

Double-Rotor Switched Reluctance Machine (DRSRM): fundamentals and magnetic circuit analysis

A novel switched reluctance machine with a double rotor configuration is introduced in this paper. The proposed design is based on optimization of the electromagnetic forces, which leads to a better electro mechanical energy conversion process. Finite Element Analysis (FEA) is used to simulate the torque characteristics and the harmonic distortion is used to evaluate the performance of the proposed motor. In the conventional machine structure the torque ripple is major drawback as the majority of the forces produced are in the radial direction that in turn does not contribute much to the torque production. However a larger torque value can be achieved if the normal forces are in the direction of motion. Double rotor exploits the fact that the same excitation produces dual magnetic paths if the reluctance between iron and air is reduced to half with increased area of flux linkage thereby maximizing the generated torque. Because of the difference in value in the radii the torque developed is not doubled due to the mechanical tolerances. However, the torque generated in double rotor is higher than conventional structures because of the reduced variable reluctance in the air gap. Both rotors are fixed to the same shaft which leads to a unidirectional torque and consequently by law of superposition, the torque generated piled up together. Based on the above motivation, the Double Rotor SRM (DRSRM) is proposed. Another advantage of the proposed DRSRM is the increase of the effective area usage for the machine structure. The results of our investigations indicate that the proposed geometry offers superior performance with improved torque characteristics with reduced THD

Performance Analysis Of Brushless Dc Motor With Optimum Magnetic Energy For Bicycle Application

Brushless DC (BLDC) motor is widely used for various applications such as transportation. BLDC motor has many advantages compared to brush motor such as more compact, high robustness and simplest construction. The maintenance of this motor also low compared to brush motor due to absent of the brush inside the motor. For electric bicycle application, the conventional motor has low electromagnetic torque because not properly designed. It faces low torque density as the motor in full load condition especially during climb uphill. In this research, an optimum magnetic energy is being determine by proper selection of permanent magnet size. In addition, this research also increases the input current in dynamic condition into the designed BLDC motor. Finite element method (FEM) is used to analyze other performance characteristic of improved motor such as back electromotive force (EMF), electromagnetic torque, flux linkage, and stator flux density. Parameter for improve the current motor are selected and varied based on the required specification. In conclusion, the research proposed the new motor specification that has highest electromagnetic torque of brushless DC motor. Finally, this research provides guidelines, suggestions and proposes a better improved structure in optimize the magnetic energy in BLDC motor

Design and implementation of double rotor switched reluctance motor using magnetic circuit analysis

With its high robustness nature and simplicity in design, the switched reluctance machines are finding its way for most of the modern day applications. The torque generating capability of such machines highly depends on the energy density available in the air-gap. The energy density in the air-gap depends on the ux traverse as the rotor moves from its full non-overlap position to the overlap position towards the excited stator pole. One way to improve the air-gap energy density is through the reduction of the air-gap length and the other through the extension of ux-linking the stator and rotor pole surface (typically known as pole-arcs). The reduction of the air-gap length is limited to a minimal value due to the mechanical oscillations that develop as the machine picks up the speed. Also the pole-arc value has to be designed appropriately in order to avoid the uneven pull due to the sequential excitations of the phases. This eventually introduces high torque ripples and vibrations inside the machine. To address this issue a dual air-gap structure through a double rotor structure is proposed in this investigation. Initially the concept of the ux tube technique based on the integration techniques used in this analysis is introduced with respect to generic dual air-gap structure. In this method the energy density of a small strip in the uniform magnetic path of the structure is computed and then integrated over the whole surface, making the computation results more accurate. Unlike the conventional ux tube techniques where estimation of ux values are used in this analytical method the results are more accurate. The algorithm to derive the magnetic characteristics of the machine is presented. A quantitative analysis is performed on the various possible pole-arc values to derive the best possible com- binations to be used in the design of the double rotor structure. It is found from the analysis that with the outer rotor pole arc at 35', the inner rotor pole arc valve at 45', the stator inner surface pole arc at 30' and the outer surface pole arc at 50' the machine exhibit lesser Total Harmonic Distortion (THD)of 13.45%. Numerical evaluation of the results from the above analysis is performed using Finite Element Analysis (FEA) tool. The maximum torque in case of the numerical FEA is about 1.755 N-m whereas by the analytical method is about 1.652 N-m. The percentage error is due to the ux shape assumption in the analytical computations. The average torque for analytical is 0.947 N-m and through numerical is 0.953 N-m. The percentage error in the computation is about 6.35%. Analysis of the design of the dual rotor structure reveals particular aspects of dificulties to assemble. A support structure for both the stator and the rotor are developed. The fabricated machine is then tested to evaluate the analytical and the simulation results. In the full overlap La the error through FEA computations is about 12.90% due to the setting of the design parameter and about 8.13% error for the analytical due to practical limitation. In the full non-overlap condition Lu the error percentage is very small and is negligible. The time taken for the FEA simulation of one point is about 2 min 30 sec and the calculation of the iterations for one position is about 10 min. Numerical com- parative evaluations of the proposed machine with its conventional structure for the same volume and same mmf value is also performed through FEA. The maximum torque generated by the selected Double rotor switched reluctance machine is about 1.755 N-m with the THD value of 13.45%. The maximum torque generated by the conventional switched reluctance machine is about 1.272 N-m with THD value of 67.13%. This analysis is performed using the finite element tool. Motor Constant Square Density (G) is used as the comparative evaluation parameter and it is found that the proposed machine exhibit 65% increase in torque value compared to that of the conventional machine