Showing 11 results for Drive
M. R. Feyzi, Y. Ebrahimi,
Volume 5, Issue 3 (9-2009)
Abstract
A switched Reluctance motor (SRM) has several desirable features, including
simple construction, high reliability and low cost. However, it suffers from large torque
ripple, highly non-uniform torque output and magnetization characteristics and large noise.
Several studies have succeeded in torque ripple reduction for SRM using Direct Torque
Control (DTC) technique. DTC method has many advantages over conventional voltage
control and current chopping mode control such as simple algorithm, less torque ripple and
instantaneous response to the torque command. In this paper, DTC method is proposed for
a 5-phase 10/8 SRM. The performance of the motor is demonstrated through the computer
simulation in Mtalab/Simulink. Then, the obtained results are verified by comparison with
the corresponding results of a 3-phase 6/4 motor performance.
M. Asgar, E. Afjei,
Volume 5, Issue 4 (12-2009)
Abstract
Switched reluctance motor (SRM) drive has a remarkable characteristic, high efficiency, and good controllability, which makes it attractive for high-speed applications. In this paper, the basic control strategy for a switched reluctance motor drive circuit is explained and then three different resonant discharge topologies for SRM drive circuit are proposed. Due to resonantly discharging of excess energy, these topologies provide faster rate of fall for the phase current, which permits the motor to operate at higher speeds. In the new circuits a capacitor is charged resonantly by the use of motor phase windings during the phase turn off periods and then discharged via an inductor and a diode during the next working strokes. Three different drive circuits utilizing this process are proposed. A detailed explanation and demonstration of the converter circuits have been presented.
A. Halvaei Niasar, E. Boloor Kashani,
Volume 10, Issue 3 (9-2014)
Abstract
In this paper, one-cycle control (OCC), as a constant-frequency PWM control strategy for current control of a six-switch brushless dc (BLDC) motor drive is investigated. Developed current regulator is a unified controller and PWM modulator. Employing the one-cycle control strategy, decreases the torque ripple resulted from the conventional hysteresis current controllers and therefore, the vibration and acoustic noise of the drive are reduced. Total operations of the system control and OCC strategy are realized by a low-cost general-purpose AVR microcontroller (Atmega8) that leads to a low-cost, high performance BLDC motor drive. Computer simulations using Matlab simulator, have been presented to show the good characteristics of this solution. Furthermore, experimental works show the excellent behavior of developed BLDC drive and agreement with simulation results.
A. Ejlali, J. Soleimani, A. Vahedi,
Volume 12, Issue 4 (12-2016)
Abstract
Recently, Transverse Flux Permanent Magnet Generators (TFPMGs) have been proposed as a possible generator in direct drive variable speed wind turbines due to their unique merits. Generally, the quality of output power in these systems is lower than multi stage fixed speed systems, because of removing the gears, so it’s important to design these kinds of generators with low ripple and lowest harmful harmonics and cogging torque that is one of the most important terms in increasing the quality of output power of generator. The objective of this paper is introducing a simple design method and optimization of high power TFPMG applied in vertical axis direct drive wind turbine system by lowest possible amplitude of cogging torque and highest possible power factor, efficiency and power density. In order to extract the output values of generator and sensitivity analysis for design and optimization, 3D-Finite element model, has been used. This method has high accuracy and gives us a better insight of generator performance and presents back EMF, cogging torque, flux density and FFT of this TFPMG. This study can help designers in design approach of such motors.
M. Sanatgar, M. R. Alizadeh Pahlavani, A. Bali Lashak,
Volume 15, Issue 3 (9-2019)
Abstract
This paper presents the control approach for single inverter dual coupled brushless DC motors (DCBLDC) drive system. One of the basic requirements of such systems, is the power balance between two motors and on the other hand, minimizing mechanical fluctuations in order to avoid mechanical equipment damage especially in the state of mechanical resonance. This paper also presents an improved form of the conventional direct torque control (IDTC) for the DCBLDC, which can be used on nine-switch inverters (NSIs). The conventional approaches used in the coupled motors are considered, and then a combination of torque and velocity control is proposed for DCBLDC. After theoretical analysis and drive modeling, whose performance has been simulated by MATLAB/Simulink in terms of dispatching balanced power as well as dealing with transient phenomena owing to malfunctioning of the mechanical connection line. Finally, experiments with the 120W BLDC motors are executed to verify the feasibility of the proposed approach.
M. El Alaoui, F. Farah, K. El Khadiri, H. Qjidaa, A. Aarab, A. Lakhssassi, A. Tahiri,
Volume 15, Issue 4 (12-2019)
Abstract
In this work, the design and analysis of new Level Shifter with Gate Driver for Li-Ion battery charger is proposed for high speed and low area in 180nm CMOS technology. The new proposed level shifter is used to raise the voltage level and significantly reduces transfer delay 1.3ns (transfer delay of conventional level shifter) to 0.15ns with the same input signal. Also, the level shifter with gate driver achieves a propagation delay of less than 0.25ns and the total area is only 0.05mm2. The proposed level shifter with gate driver was designed, simulated and layouted in Cadence using TSMC 180nm CMOS technology.
P. Gupta, S. K. Jana,
Volume 17, Issue 2 (6-2021)
Abstract
The advancement in the integrated circuit design has developed the demand for low voltage portable analog devices in the market. This demand has increased the requirement of the low-power RF transceiver. A low-power phase lock loop (PLL) is always desirable to fulfill the need for a low power RF transceiver. This paper deals with the designing of the low power transconductance- capacitance (Gm-C) based loop filter with the help of the gate-driven quasi bloating Bulk (GD-QFB) MOS technique. The GD-QFB MOS-based operational transconductance amplifier (OTA) has been proposed with a high dc gain of 82.41 dB and less power consumption of 188.72 µW. Further, Gm-C based active filter has been designed with the help of the proposed GD-QFB OTA. The simulation results of Gm-C filter attain a -3 dB cut-off frequency of 59.08 MHz and power consumption of 188.31µW at the supply voltage of 1V. The proposed Gm-C filter is suitable for the designing of 1-3 GHz low power PLL.
H. Azizi Moghaddam, A. Farhadi, S. Mohamadian,
Volume 18, Issue 2 (6-2022)
Abstract
In the new advanced drive schemes, identification and modeling of the load complex characteristics can play an important role to predict the dynamic performance of the proposed control strategy. The novelty of this paper consists in the classification of the different types of the nonlinear loads which the electrical drive systems may encounter. In this study, nonlinear components of mechanical loads are divided into two groups. The first type includes nonlinear phenomenon caused by the nature of load which is predictable and identifiable. Another type of loads nonlinear characteristic happens due to the occurrence of a mechanical fault in motor, coupling or load parts. Generally, this type of non-intended nonlinear effect is not predictable and often occurs in the installation and operation stage of the drive system utilization. In this paper, the performance of an induction servo drive system has been simulated under the influence of different types of non-linear industrial loads.
S. M. Ahmed, K. S. Ahmed, Y. M. Shuaib,
Volume 19, Issue 1 (3-2023)
Abstract
This article discusses the operating principle and simulation of closed loop control of a three phase induction motor (IM) powered by five level diode clamped multilevel inverter (DCMLI) using direct torque control (DTC) technique. The main purpose of this article is to regulate the torque and speed of an IM and to decrease total harmonic distortion (THD). In this article, a five-level inverter's direct modulation approach with the dc link voltage self-balancing is presented. To reduce capacitor voltage variation, the redundancies of various switch topologies for the creation of intermediate voltages are also used. The use of LC filter results in lower output voltage and current distortion. A multicarrier PWM control technique is used for DCMLI to provide high quality sinusoidal output voltage with decreased harmonics. This can be obtained by employing Sinusoidal Pulse Width Modulation (SPWM) method for speed and torque control. This demonstrates that the recommended method of controlling the motor's speed and torque is effective. The simulation result reveals that DTC for the five-level inverter fed IM drive gives a rapid dynamic response, lower voltage and current THDs, and much less flux and torque distortion. The simulation is carried out in MATLAB Simulink (R2014).
A. O. Akande, F. A. Semire, Z. K. Adeyemo, C. K. Agubor,
Volume 19, Issue 2 (6-2023)
Abstract
The quality of signal at a particular location is essential to determine the performance of mobile system. The problem of poor network in Lagos, Nigeria needs to be addressed especially now that the attention is toward online learning and meetings. Existing empirical Path Loss (PL) models designed elsewhere are not appropriate for predicting the 4G Long-Term Evolution (LTE) signal in Nigeria. This research developed a modified Okumura-Hata model in 4G network. The Okumura-Hata model being the closest to the measured values was modified using the PL exponent. The modified model was enhanced by Gravitational Search Algorithm (GSA). The measured data, modified and existing models were simulated using MATLAB R2018a software. Root Mean Square (RMSE) was used to evaluate the performance modified and existing and models. The result showed that Enhanced GSA model outperformed the existing models. The study successfully developed a modified PL model for LTE in Lagos, Nigeria. Therefore, modified model will be a good model in network planning for voice and fast online data connection in 4G LTE network.
Ehsan Ghasemi, Seyyed Mohammad Razavi, Sajad Mohamadzadeh,
Volume 20, Issue 4 (11-2024)
Abstract
This study proposes a descriptor-based approach combined with deep learning, which recognizes facial emotions for safe driving. Paying attention to the driver's facial expressions is crucial to address the increasing road accidents. This project aims to develop a Facial Emotion Recognition (FER) system that monitors the driver's facial expressions to identify emotions and provide instant assistance for safety control. In the initial stage, Viola-Jones face detection was employed to detect the facial region, followed by Butterworth high-pass filtering to enhance the identified region for locating the eye, nose, and mouth regions, using Viola-Jones face detection. Secondly, the Local Binary Patterns (LBP) feature descriptor is utilized to extract features from the identified eye, nose, and mouth regions. Using 3 RGB channels, the extracted features from these three regions are fed into RessNet-50 and EfficientNet deep networks. The outputs of the two deep learning models' classifiers are combined and integrated using two ensemble methods: ensemble maximum voting and ensemble mean. Based on these combining classifier rules, the performance was evaluated on the JAFFE and KMU-FED databases. The experimental results demonstrate that the proposed method can effectively and with higher accuracy than other competitors recognize emotions in the JAFFE and KMU-FED datasets. The novelty and originality of this paper lie in its significant application in the automotive industry. Implementing our proposed method in a system capable of high accuracy and precision can help mitigate numerous driving hazards. Our approach has achieved 99% and 98% accuracy on the JAFFE and KMU-FED databases, respectively. This high level of accuracy, coupled with its practical relevance, underscores the innovative nature of our work.
