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The commutation points of the Brushless DC motor in the sensored mode of operation are synchronized with discrete rotor position detection signals from three Hall effect sensors. Therefore, any delay in the hall sensor signals results in delayed commutation, which disturbs synchronization with the motor Back Electromotive Force (BEMF) profile. The classical methods to correct this commutation delay include phase advancing schemes that utilize BEMF profiling, zero crossing detection, virtual neutral point creation, and system architecture or control scheme modifications. This paper presents a method for estimating the commutation delay in electrical degrees using the proposed estimation relation with DC link current for fault effect minimization. The proposed method can be easily implemented in actual controllers without hardware change requirements. The proposed method is established and tested using MATLAB Simulink models for two motors with different delay angle values. The proposed method is tested on the experimental test bench of a controller with a 1 kW BLDC motor of an electric rickshaw under different load conditions. Simulation and hardware test results show the mean estimated commutation delay lying within ± 1° electrical of the actual value under various error and load conditions. The corrections implemented according to the estimated delay angles result in reduction of peak-to-peak DC link current, increase in the nominal torque generated per ampere, and reduction in the DC current ripple content. Simulation and experimental results confirm reduction in the effect of commutation delay and verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

In this study, the most promising technology available, a fuel cell stack called a "Polymer-Electrolyte Membrane (PEMFC)," is used to power a brushless DC motor. To enhance the PEMFC's functionality, a robust "maximum power point tracking" (MPPT) algorithm was used in the DC/DC boost circuit. The "perturbation and observation" (P&O) method was developed for this purpose. In this paper, we present a self-tuning PI-fuzzy logic controller (FLC) for the speed of brushless DC (BLDC) motors. The effectiveness of the proposed controller was evaluated using simulated load disturbances and reference speed fluctuations. Hence, the rise time (R.T), settling time (S.T), steady-state error (S.S.E), overshoot (OVER), undershoot (UNDER), peak time (P.T), and peak value (P.V) are computed and examined as part of the required control performance characteristics. PEMFC source optimization with load variation and BLDC speed regulation is the key contribution of this study. The findings of this study have the potential to lead to the development of more efficient, sustainable energy systems that would be good for the planet and cheaper to operate. The results further demonstrate that the controller performs admirably across a wide range of speeds and loads since the PEMFC battery reliably supplies the power required for the BLDC motor. [ABSTRACT FROM AUTHOR]

This paper presents the development of an optimization and modeling method for the objective functions of output power, efficiency and weight of an outer rotor permanent magnet brushless DC (BLDC) motor based on radial basis function (RBF) approximation technique. The proposed RBF‐based Pareto optimization method requires less knowledge about electric/magnetic formulas and can replace conventional optimizations based on these equations with higher accuracy. To apply the proposed optimization method, the initial design should be developed using such equations. Therefore, RBFs are used to model and predict engine behavior. To optimize the objective functions, we used a genetic algorithm optimization technique with nonlinear electric and magnetic constraints to find the Pareto front set. The design obtained by the proposed radial basis function Pareto optimization (RBFPO) method was finally verified by Ansoft Maxwell. The results of optimal design using the RBFPO method have higher output power and efficiency. Also, in addition to the advantage of a favorable accuracy, RBF‐based models are significantly faster than models available in simulation tools. [ABSTRACT FROM AUTHOR]

This study presents the tilt integral derivative (TID) controller technique for controlling the speed of BLDC motors in order to improve the real-time control of brushless direct current motors in electric vehicles. The TID controller is applied to the considered model to enhance its performance, e.g., torque and speed. This control system manages the torque output, speed, and position of the motor to ensure precise and efficient operation in EV applications. Brushless direct current motors are becoming more and more popular due to their excellent torque, power factor, efficiency, and controllability. The differences between PID, TID, and PI controllers are compared. The outcomes demonstrated that the TID control enhanced the torque and current stability in addition to the BLDC system's capacity to regulate speed. TID controllers provide better input power for BLDC (brushless DC) drives than PI and PID controllers do. Better transient responsiveness and robustness to disturbances are features of TID controller design, which can lead to more effective use of input power. TID controllers are an advantageous choice for BLDC drive applications because of their increased performance, which can result in increased system responsiveness and overall efficiency. In an experimental lab, a BLDC motor drive prototype is implemented in this study. To fully enhance the power electronic subsystem and the brushless DC motor's real-time performance, a test bench was also built. [ABSTRACT FROM AUTHOR]

Brushless synchronous machines (BSMs) are replacing conventional synchronous machines with static excitation in generation facilities due to the absence of sparking and lower maintenance. However, this excitation system makes measuring electric parameters in the rotor challenging. It is highly difficult to detect ground faults, which are the most common type of electrical fault in electric machines. In this paper, a ground fault detection method for BSMs is proposed. It is based on an inductive AC/DC rotating current sensor installed in the shaft. In the case of a ground fault in the rotating parts of the BSM, a fault current will flow through the rotor's sensor, inducing voltage in its stator. By analyzing the frequency components of the induced voltage, the detection of a ground fault in the rotating elements is possible. The ground faults detection method proposed covers the whole rotor and discerns between DC and AC sides. This method does not need any additional power source, slip ring, or brush, which is an important advantage in comparison with the existing methods. To corroborate the detection method, experimental tests have been performed using a prototype of this sensor connected to laboratory synchronous machines, achieving satisfactory results. [ABSTRACT FROM AUTHOR]

Stator turn-to-turn faults occur due to improper loading, eccentricity in the rotor, and increases in the operating temperature. During the occurrence of a stator turn-to-turn fault, an abnormal temperature increase occurs, and if this state is left unattended for a long duration, it can lead to degradation of the permanent magnet. This paper presents an analytical modeling scheme for surface permanent magnet brushless DC motors for diagnosing and classifying stator turn-to-turn faults using SIMULINK® during non-stationary operating conditions. A significant increase in the stator current, back EMF, torque, and speed is observed. A current signature analysis is performed during non-stationary operating conditions using a fast Fourier transform method to identify the severity of the fault. Furthermore, a simple and efficient classification model is developed by selecting the best classifier among the decision trees, neural network, support vector machine, discriminant analysis, and ensemble classifier. A statistical evaluation of the current signal for fault feature extraction and ranking is performed based on minimum redundancy and maximum relevance, Chi-square test, Relief F, analysis of variance, and Kruskal–Wallis test. The dataset for classification is extracted from a Simulink analytical model. Neural network-based classifiers can classify faults precisely and rapidly with a minimum number of features. [ABSTRACT FROM AUTHOR]

This paper proposed a double-sided staggered conical teeth traveling wave rotating ultrasonic motor based on in-plane bending mode, which reduces the difficulty of rotor preload application and improves the output characteristics of in-plane bending mode traveling wave rotating ultrasonic motor. The motor has four sets of drive teeth alternately distributed on both the inner and outer sides of the vibrator, with the drive teeth gap dedicated to accommodate the piezoelectric ceramic piece, and the staggered drive teeth on both sides of the vibrator are used to drive the rotor rotation. The motor operates in two in-plane third-order bending modes with the same frequency and orthogonal to each other, and is excited by four sets of piezoelectric ceramic disks spaced 90 degrees apart from the inner and outer sides. After the prototype was completed, its vibration characteristics and output performance were experimentally tested, and the actual effects of the three excitation schemes were compared. The experimental results show that the motor can provide a maximum output torque of 1.82N-mm and a maximum no-load speed of 96.4 rpm when the excitation voltage is 300 V and the excitation frequency is 20.60 kHz. [ABSTRACT FROM AUTHOR]

Aiming at the problem of difficulties in heat dissipation for a permanent magnet synchronous motor (PMSM) with high power/torque density, the effect of motor length‐to‐diameter ratio (r0) on the selection of cooling water channels is investigated from the perspective of the geometric parameters of the PMSM in this paper. First, the 3‐D fluid–solid coupled heat transfer models of three actual motors with the length‐to‐diameter ratios of 0.27, 0.81 and 2.04 are established. Every model is calculated under spiral, axial and circumferential cooling water channels, respectively. The cooling effect, cooling energy loss and motor thermal balance are compared and analyzed. Then the optimal cooling water channel for each of three motors is confirmed. Further, the motor temperature rise and fluid differential pressure are plotted. The threshold of motor length‐to‐diameter ratios is determined at which the overall performance of the axial and circumferential cooling water channel is highly similar. The general conclusions of selection of cooling water channels for PMSMs with different geometry shape are summarized. Finally, a prototype with r0 = 0.27 is fabricated and tested, verifying the validity of the fluid–solid coupling simulation analysis. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This study provides an efficient torque and speed control method for brushless DC (BLDC) motor utilizing a fractional order proportional integral derivative (FOPID) controller based on the multiverse optimization algorithm and salp swarm optimization (SSO). When combined with a solar photovoltaic (PV) system and a voltage boosting architecture, standard PID controllers regulated the BLDC drive parameters due to their simplicity and improved steady-state performances. A solar PV system with a specific power range is chosen for the best output solution on the output side. The MPPT method employed is the incremental conductance approach for tracking maximum power from the source. However, it has a problem with unpredictability owing to load changes. The PID controller tuning also relates to the structure's parametric uncertainties. Therefore, precise control methods may be offered with the aid of the FOPID controller to address the aforementioned issues. Simulation results of the proposed MVO and SSO-based FOPID controller for BLDC speeds run in the Matlab Simulink platform. To confirm the adaptability of the suggested control scheme for BLDC motor, the outcomes are interrelated using genetic algorithm, gray wolf, and PSO-based FOPID controllers. [ABSTRACT FROM AUTHOR]

This paper proposes solutions for zero-value-cross detection (ZVCD) in a single-phase mains-powered motor used for high-torque tightening. Four different applications are presented: resistor-polarized digital input, a resistor-polarized optocoupler, comparators steering up the optocoupler, and n-MOSFETs polarizing the optocoupler. The performance of each solution is evaluated in terms of complexity, dimensions, power dissipation, and response time. The n-MOSFET-based solution is found to be the most suitable, providing a simple design, low power dissipation, and almost instantaneous response. This solution meets the project's requirements for accurate and fast zero-crossing detection. [ABSTRACT FROM AUTHOR]

The hydraulic motor will generate noise in operation and it has fluid-structure coupling and compact internal structure. The sound intensity measurement is difficult to distinguish the noise sources of motor. In this paper, a high-precision localization method for noise sources of bent-axis motor is studied to improve the resolution of the sound intensity images to locate noise sources accurately. Firstly, the structural characteristics of the motor are analyzed, and the sound intensity images are obtained through the experiment. Then the high-resolution optimization method based on compressed sensing is designed according to the characteristics of the sound intensity field. Finally, the sound intensity images with high resolution are constructed. The high-resolution images can distinguish the position of the prominent points, and the error is less than 0.4 dB. The identification distance of noise sources can reach 30 mm, and it breaks through the highest resolution of the traditional sound intensity test. [ABSTRACT FROM AUTHOR]

Terminal neurological conditions can affect millions of people worldwide and hinder them from doing their daily tasks and movements normally. Brain computer interface (BCI) is the best hope for many individuals with motor deficiencies. It will help many patients interact with the outside world and handle their daily tasks without assistance. Therefore, machine learning-based BCI systems have emerged as non-invasive techniques for reading out signals from the brain and interpreting them into commands to help those people to perform diverse limb motor tasks. This paper proposes an innovative and improved machine learning-based BCI system that analyzes EEG signals obtained from motor imagery to distinguish among various limb motor tasks based on BCI competition III dataset IVa. The proposed framework pipeline for EEG signal processing performs the following major steps. The first step uses a meta-heuristic optimization technique, called the whale optimization algorithm (WOA), to select the optimal features for discriminating between neural activity patterns. The pipeline then uses machine learning models such as LDA, k-NN, DT, RF, and LR to analyze the chosen features to enhance the precision of EEG signal analysis. The proposed BCI system, which merges the WOA as a feature selection method and the optimized k-NN classification model, demonstrated an overall accuracy of 98.6%, outperforming other machine learning models and previous techniques on the BCI competition III dataset IVa. Additionally, the EEG feature contribution in the ML classification model is reported using Explainable AI (XAI) tools, which provide insights into the individual contributions of the features in the predictions made by the model. By incorporating XAI techniques, the results of this study offer greater transparency and understanding of the relationship between the EEG features and the model's predictions. The proposed method shows potential levels for better use in controlling diverse limb motor tasks to help people with limb impairments and support them while enhancing their quality of life. [ABSTRACT FROM AUTHOR]

The wheel motor drive system is one of the structure transmission schemes in an electric tractor. The coordinated control of electronic differential speed and torque can significantly improve the energy utilization of tractors. The motor of the electric tractor can also be urgently required for the energy conversion device for higher energy, efficiency, and reliability, compared with the traditional fuel tractors. Among them, the finite element (FE) method can be used to accurately predict and evaluate the electromagnetic performance of the wheel drive motor in electric tractors and then to optimize the structure of the electromagnetic converter. However, traditional models cannot consider the bidirectional magnetic-thermal coupling between the electromagnetic and temperature field, leading to the low prediction accuracy of the model. In this work, the FE model was developed and then verified by a series of experiments. A kind of 12-slot, 7-pole brushless DC wheel drive motor with the reducer was also taken as the research object. Dynamic characteristics of the motor were then analyzed under no-, half- and rated loading. Simulation results show that there was no magnetic leakage, where the flux density was in the unsaturated state under no-load conditions. The loss of copper, iron, and eddy current in the motor rose dramatically with the increase of the load, where the copper loss increased the most. Specifically, the copper losses of the motor tended to be 0, 60, and 340 W, respectively, under no-, half- and rated loading. The average core losses were 9, 15, and 22 W, respectively, whereas, the average eddy current losses were 11, 32, and 58 W, respectively, under the three load conditions. The magnetothermal bidirectional coupling model of the motor was then constructed to simulate the distribution of the temperature field. The results demonstrated that the highest temperature of the motor occurred on the permanent magnets under three working conditions. Temperatures of permanent magnets were elevated by 54.61, 77.63, and 87.10 °C, respectively. In addition, the air-gap width, stator-notch width, spacing, and the width of the permanent magnet were set as the variables, while the groove torque, torque density, and permanent magnet loss were taken as the optimization objectives. A two-layer multi-objective optimization was proposed to improve the optimization efficiency and accuracy using Taguchi and response surface. The optimal structural parameters were determined as follows: The optimized spacing between permanent magnets, the width of permanent magnets, the air-gap width, and stator-notch width were 0.4, 3.5, 1.1, and 4.75 mm, respectively. Simulation results showed that the motor torque density increased by 8% compared to that before optimization, whereas, the permanent magnet loss decreased by 18.6%. The bench test of the prototype showed that the groove torque of the motor was reduced by 20.9% after optimization, indicating the effectiveness of the optimization. This finding can provide a strong reference to promote motor performance. [ABSTRACT FROM AUTHOR]

This paper presents a topology for the brushless operation of a wound-rotor synchronous machine based on the subharmonic excitation technique by using two sets of multi-pole windings on the armature as well as on the rotor. The armature windings consist of a four-pole three-phase main winding and a two-pole single-phase additional winding, responsible for the generation of fundamental and subharmonic components of magnetomotive force (MMF), respectively. The rotor contains four-pole field winding and two-pole excitation winding. From the generated air gap MMF, the additional winding is responsible for induction in excitation winding, which feeds DC to the field winding through a rotating rectifier without the need of brushes. Then, the interaction of the magnetic field from the main and the field windings produces torque. The proposed topology is analyzed using 2D finite element analysis (FEM). From the analysis, the generation of the subharmonic component of MMF is verified, which helps in achieving the brushless operation of the wound-rotor synchronous machine. Furthermore, the performance of the proposed brushless multi-pole topology is compared with the existing dual three-phase winding multi-pole topology in terms of current due to induction, output torque, torque ripples, and efficiency. [ABSTRACT FROM AUTHOR]

This paper addresses with the development of an effective standalone solar photovoltaic (PV)‐fed brushless DC (BLDC) motor water pumping system with battery storage. The system guarantees continuous water supply in all operating environments. Boost converter is selected as the DC‐DC converter linking the PV array and voltage source inverter. Maximum power point tracking is achieved through perturb and observe algorithm. The bidirectional buck‐boost converter is intended for the transfer of power between the battery and solar panels. Charging and discharging control of battery is achieved through one‐cycle control of bidirectional converter which provides quick response and zero steady‐state error. The BLDC motor works with electronic commutation providing smooth and fundamental frequency operation of the voltage source inverter. Simple battery management system using digital integrated circuits for controlling the power transfer amidst the solar panel and the load enhances the system efficiency. The performance of the proposed system is checked for various operating modes like normal conditions, discharging conditions and charging conditions of the battery, and is validated through simulation results. Comparison with existing topologies proves the efficacy of the system under all operating conditions. [ABSTRACT FROM AUTHOR]

This paper introduces a brand-new, inspired optimization algorithm (the chaotic billiards optimization (C-BO) approach) to effectively develop the optimal parameters for fuzzy PID techniques to enhance the dynamic response of the solar–hydrogen drive of an induction motor. This study compares fuzzy-PID-based C-BO regulators to fuzzy PID regulators based on particle swarm optimization (PSO) and PI-based PSO regulators to provide speed control in solar–hydrogen, induction-motor drive systems. The model is implemented to simulate the production and storage of hydrogen while powering an induction-motor drive which provides a great solution for the renewable energy storage problem in the case of solar pumping systems. MATLAB/Simulink 2021a is used to simulate and analyze the entire operation. The laboratory prototype is implemented in real time using a DSP-DS1104 board. Based on the simulation and experimental results, the proposed fuzzy-PID-based C-BO has reduced speed peak overshoot by 45.3% when compared to a fuzzy PID based PSO speed regulator and by 68.13% when compared to a PI-based PSO speed controller in the case of a large-scale motor. Additionally, the proposed speed regulator has a 6.1% faster speed rising time than a fuzzy-PID-based PSO and a 9.5% faster speed rising time than a PI–PSO speed controller. It has an excellent dynamic responsiveness value when compared to the other speed regulators. [ABSTRACT FROM AUTHOR]

In view of the current new energy vehicles only implement torque control on the drive motor, resulting in the engine speed fluctuation, affecting the vehicle running stability and reducing the engine efficiency and energy saving effect, a new energy vehicle engine speed control method based on Internet of vehicles technology is proposed. The battery and operation data are obtained through the sensor of the new energy vehicle Internet of vehicles, and the data are controlled and transmitted by the controller area network. The overall external dynamic characteristics of the engine are analyzed by using the average value model. According to the principle of engine dynamic system, the throttle intake manifold model, combustion torque model and power output sub model are constructed respectively. The speed is controlled by double working points According to the variable parameter PID control of the engine, the load prediction is introduced to optimize the speed control, and the internal pressure value of the accumulator is obtained through the SOP value to realize the speed control of the new energy vehicle engine. The experimental results show that the engine speed control method can effectively improve the energy-saving effect and efficiency of the engine, reduce the engine speed fluctuation, and improve the vehicle running stability under the condition of meeting the driver's torque demand. [ABSTRACT FROM AUTHOR]

This paper aims at highlighting the behaviour of universal fractional-horsepower commutation motor in different operating situations, by using modern means of investigation. For this purpose, a series of direct current and alternating current experimental tests were carried out, with and without compensation winding. The paper presents partial photos of the test stand, the circuit schemes used and the figures obtained from the experiments. From this last category, there are emphasized the phasor representations obtained and the harmonic analyses of the monitored currents. The paper ends with conclusions and references. [ABSTRACT FROM AUTHOR]

The control systems at Air handling units (AHUs) have nonlinear nature, resulting potentially in sluggish, aggressive, or oscillatory responses under variable operation conditions. This paper is to develop an approach for evaluating the nonlinear control performance of AHUs under variable operation conditions and for identifying the impact of varying multiple operation parameters which guides controller design. To do so, an operation parameter-based root distribution technique, intended to sketch the paths traced by closed-loop poles as multiple operation parameters are varied, is first introduced. The technique—which may be viewed as an extension of conventional, single-variable root locus—is then applied to a fan speed control system that includes a motor with a variable frequency drive and a supply fan with an air duct under variable fan speed and duct static pressure. Using the technique, the system's stability region is graphically identified. The system is also found to be aggressive and gradually lose its stability as the fan speed decreases and the duct static pressure increases, which is validated by the field tests. The root distribution approach is an effective tool to evaluate the performance of any nonlinear control systems at AHUs with multiple variable operation parameters without requiring time-domain simulations. [ABSTRACT FROM AUTHOR]

With the development of science and technology, the rapid development of social economy, the motor as a new type of transmission equipment, in the production and life of people occupies a pivotal position. Under the rapid development of computer and electronic technology, manufacturing equipment is becoming larger, faster, more continuous, and more automated. This has resulted in complex, expensive, accident-damaging, and high-impact equipment for electric motors; even routine maintenance requires significant equipment maintenance and maintenance costs. If a fault occurs, it will cause serious damage to the entire equipment and can even have a major impact on the entire production process, leading to a serious economic and social life. In this paper, a CNN-based machine learning fault diagnosis method is proposed to address the problem of high incidence of motor faults and difficulty in identifying fault types. A fault reproduction test is constructed by machine learning techniques to extract vibration time domain data for normal operating conditions, rotor eccentricity, stator short circuit, and bearing inner ring fault; divide the data segment into 15 speed segments, extract 13 typical time domain features for each speed segment; and perform mathematical statistics for fault diagnosis. Compared with the traditional algorithm, the method has more comprehensive feature information extraction, higher diagnostic accuracy, and faster diagnostic speed, with a fault diagnosis accuracy of 98.7%. [ABSTRACT FROM AUTHOR]

This article proposes a multiobjective optimization design framework for a double stator brushless hybrid excitation motor (DSBHEM) to provide high torque, wide flux regulation ability and low torque ripple. The design variables are divided into sensitive level and insensitive level by sensitivity analysis. The response surface model (RSM) and nondominated sorting genetic algorithm 2 (NSGA2) are organically combined to generate a set of Pareto solutions for the sensitive level variables, from which the optimal values of the sensitive level variables are obtained. In addition, the optimal values of insensitive variables are obtained through single parameter scanning optimization, and a set of final optimal design variables are obtained. The electromagnetic performance of the initial design and the optimal design are compared with finite element analysis. Finally, a prototype is manufactured to verify the proposed concepts. [ABSTRACT FROM AUTHOR]

When compared to electrically modulated brakes (EMBs), such as a magnetic particle brake, modern brushless direct current (BLDC) motors have substantially higher power densities, and therefore have become an attractive alternative to EMBs for applications requiring controllable modulated resistance (i.e., torque-controllable braking). Unlike brakes, however, which fundamentally guarantee strict passivity, emulating mechanical resistance with a motor does not guarantee passive behavior. In order to enable the use of a motor as a torque-controllable brake with fundamentally guaranteed passivity, this paper presents a control scheme that provides high-fidelity torque tracking and physically guarantees strictly passive behavior. Specifically, this paper: (1) describes model-based control methods for applications requiring high-fidelity torque control and strictly passive impedance; (2) presents an analysis that characterizes the limits of control and tradeoffs of controllability and energy generation associated with using a motor in this manner; and (3) presents experimental results that validate both the system characterization and control performance for the strictly passive controllable impedance approach. [ABSTRACT FROM AUTHOR]

Virtual synchronous generator (VSG)-based control approaches for AC machine drivers have attracted much attention in recent years. The contradiction between the strong motor loading capacity and the small DC voltage fluctuation is disregarded in previous studies. A larger virtual inertia is required to raise the torque gain and drive the motor with heavier loads, thus resulting in greater DC voltage variations. A systematic method is proposed for the optimal design of the virtual inertia for VSG-based motor starting systems to achieve the maximal motor loading capacity and the low DC voltage fluctuation in this paper. Firstly, the relationship between the virtual inertia and the loading capacity is revealed on the basis of the closed-loop analysis. Considering the DC voltage variation, the constraint on the maximal value of the virtual inertia is proposed from the energy-balance perspective despite the unknown contribution of the DC capacitors to the virtual inertia. To fully exploit the energy storage capacity of the DC capacitors and raise the upper limit of the virtual inertia under the same permitted DC voltage variation, a modified DC voltage reference is introduced. Extensive simulation and experimental results are presented to validate the effectiveness of the proposed methods. [ABSTRACT FROM AUTHOR]

Spoke-array brushless dual-electrical-port dual-mechanical-port (SA-DEP-DMP) machine is a good candidate for continuously variable transmission device, because of its high compactness, contactless torque transmission, and decoupled rotors. Due to the specific features, including two independent controllable rotors, two set windings, and complex magnetic field coupling, some unique design considerations of SA-DEP-DMP machine are analyzed in this article. First, there is a little accurate analytical model for DEP-DMP machine. An applicable analytical model is proposed to directly describe the characteristic of air-gap magnetic field and calculate the sizing equation. The key innovation is that the inner air-gap permeance with the slot effect is mapped into the magnetic potential by air-gap mapping model, which simplifies the double air-gap structure into a single air-gap structure. Second, the torques of two rotors are always optimized separately at the same time. Using this design method, the optimal torques of two rotors cannot achieve simultaneously for many parameters. In order to solve this problem, a novel constant torque ratio design method is proposed where two windings electric loading distributions are considered. The influences of key parameters, such as combination of slot and pole, stator split ratio, permanent magnet size, etc., on the torque performances are analyzed based on finite-element analysis. Finally, an SA-DEP-DMP prototype is manufactured. [ABSTRACT FROM AUTHOR]

In order to study the method for reducing the losses in cryogenic permanent magnet motors for LNG pumps, the design of a submersible cryogenic permanent magnet brushless DC motor is presented in this paper. First, the materials used in the motor were tested at room temperature and at a low temperature, and the BH curve and BP curve of the silicon-steel sheet were obtained. Next, DC power supply and PWM power supply were used to analyze the influence of the power-supply mode on the motor loss. Finally, based on the calculation results of the motor loss, the ability of the copper-shielding layer to reduce the motor loss was explored. In the calculation process, the influence of the temperature was considered, and the motor losses at different temperatures were compared and analyzed, which provided a reference for reducing the loss of the cryogenic permanent magnet motor. [ABSTRACT FROM AUTHOR]

Motors are one of the vital equipment and generally the higher in numbers in oil and gas processing facilities. The primary function is to drive the process equipment such as compressors, fans, pumps etc. Unreliability of the motors is a threat to safety but also to production loss and high operating expenditure. Motors experience higher failure rates and maintenance costs with age due to lower focus during useful life periods. In order to properly address the long-term reliability and maintainability of the motors and associated subsystems, this paper aims to propose a structured methodology and set of tools to ensure effective assessment. The proposed model mainly consists of data collection, analysis, assessment, financial analysis and later developed actions to properly address the concerns. Equipment failure and repair data is a challenge to any reliability assessment; hence, proposed methodology was introduced to collect, verify and validate the data. Later, multiple tools such as Pareto Analysis, Failure Mode and Effect Analysis and Root Cause Analysis were used to perform a detailed assessment. Weibull analysis was also explored to understand the failure modes, which ultimately helped in improving the availability of the motors. The proposed methodology has been applied to high-voltage motors to observe the effectiveness of the tools and proposed model in addressing reliability and maintainability. The results show significant reliability improvements of 12% (from 58% to 70%) and prove that the structured method can be effectively used in complex process facilities with significant benefits. [ABSTRACT FROM AUTHOR]

Single-mode linear ultrasonic motors (SMLUMs) have the advantages of excellent accuracy, long travel distance, single vibration mode and simple driving scheme, which have been applied in precision positioning and micro/nano manipulation actuators. However, it is still challenging to accurately and efficiently analyze such motors due to their complicated electro-mechanical coupling behaviors under contact-based operating conditions. This paper proposed an improved equivalent circuit model for a single-mode linear ultrasonic motor considering the real contact-based operating conditions, where a new actuation mode of the V-shape transducer is adopted. The electro-mechanical coupling characteristics of the stator under contact-based boundary condition is modeled by a modified admittance-type equivalent circuit, where the variable contact stiffness and loss are characterized between the stator and the mover. The friction drive mechanism is modeled by a thyristor rectifying circuit to characterize the intermittent actuation characteristics, and the nonlinear relationship between the motor characteristics and the contact-based operating conditions is initially characterized from the circuit viewpoint. The merits and the applications of the circuit-based model are exemplified by parameter identification and modification, losses segregation, admittance characteristics analysis and output and control characteristics evaluation for such SMLUMs. [Display omitted] • The real contact-based operating conditions are considered in equivalent circuit modeling. • The friction drive mechanism is initially characterized and clarified from circuit viewpoint. • A circuit-based method is proposed to conduct segregation and evaluation of various losses. • The motor output and control characteristics can be evaluated by the proposed model. [ABSTRACT FROM AUTHOR]

This study focused on approaches for reducing torque ripples in Permanent Magnet Brushless Direct current motors (PMBLDC) to provide sophisticated performance and reliable machine drives for both industrial and consumer applications. Torque ripples are caused by current ripple, nonsinusoidal Back Electromotive Force (EMF), and cogging torque at the Brushless Direct Current Motor (BLDCM) output. Acoustic emissions are produced when the torque ripple creates vibrations in the mechanical system, which interacts with the motor housing and reduces the life span of the motor. The BLDC's uses are limited due to these acoustic emissions. Proportional-Integral (PI), Fuzzy Logic Control (FLC), and Adaptive Neuro-Fuzzy Inference System (ANFIS) speed controller approaches were used to construct and analyze the mathematical model of the BLDC motor in the MATLAB environment. The Adaptive Neurofuzzy Inference System (ANFIS) speed control system has solved the shortcomings of the PI and Fuzzy Logic Control (FLC) techniques. Because of FLC interpolation and flexibility, ANFIS is one of the finest trade-offs between neural and fuzzy systems, allowing for smooth control. Model compactness, a smaller training set, and faster convergence are all benefits of the ANFIS approach over traditional feedforward NN. In this research proposal, a simple control approach based on outgoing phase current discharge hysteresis control (OGCDHC) with minimal torque ripple is presented. [ABSTRACT FROM AUTHOR]

This paper presents a subharmonic-based brushless wound rotor synchronous machine (BL-WRSM) topology with permanent magnet-assisted (PMA) and consequent-pole (CP) rotor structures to achieve better torque characteristics as compared to the conventional subharmonic-based brushless WRSM. The proposed topologies use the conventional high-efficient subharmonic field excitation technique to achieve a brushless operation and a lower volume of permanent magnet (PM) to achieve better average, starting, maximum, and minimum torques and lower torque ripple. A four-pole, twenty-four-slot (4-pole/24-slot) machine with conventional, PM-assisted (PMA), and consequent-pole (CP) rotor structures are developed in a JMAG-Designer 20.1 environment to carry out two-dimensional finite element analysis (2D-FEA). The developed machines are used to validate the operation and achieve electromagnetic and electromechanical performances of the proposed subharmonic-based BL-WRSM topologies with better torque attributes. [ABSTRACT FROM AUTHOR]

With the developing technology, direct current motors have been widely used in industrial applications. The limited use of brushed models in some areas has made Brushless Direct Current Motors stand out. In this paper, the design and analysis of an efficient, high power density, brushless direct current motor (BLDC) for use in electric vehicles is carried out. In this direction, studies have been carried out to reduce the reverse induced voltage, which is the biggest problem of electric motors in the electric vehicle sector. Analyzes were carried out with ANSYS subprograms, which realized a Finite Element Method (FEM) based solution to change the nominal values of the BLDC motor by changing the distance between the rotor and the stator. According to the results of the analysis, it was concluded that the method used in the study can also be used in high speed applications of brushless direct current motors. [ABSTRACT FROM AUTHOR]

A comparative study of new partitioned stator hybrid excitation axial flux switching permanent magnet (HEAFSPM) motors with different partitioned excitation stator topologies for in-wheel traction applications is presented in this paper. The realization approaches of the partitioned stator HEAFSPM motor are discussed, and the motor topology with windings and permanent magnets (PMs) separately setting on different stators is selected in view of the advantageous structure for thermal management. On this basis, two partitioned excitation stator topologies including C-type tooth core and T-type tooth core stator configuration are proposed, and the air-gap flux modulation and flux regulation principle of the motors are analyzed. In addition, the design method of the partitioned stator HEAFSPM motor considering the effect of hybrid excitation sources is provided, and the two motors with different tooth cores are designed respectively. Meanwhile, for a fair comparison, the multiple objectives optimization method coupled with the sensitivity analysis is employed to optimize the two motors. The electromagnetic performances, anti-demagnetization capability, and flux regulation performance of the two motors are all investigated in detail. Finally, two prototype motors are fabricated and tested. Both the theoretical analysis and experimental results verify the effectiveness and reasonability of the motor. [ABSTRACT FROM AUTHOR]

Accurate commutation point is essential to ensure the ideal torque performance and low power consumption for brushless DC (BLDC) motor. In order to achieve the precise sensorless commutation at a constant or the rapidly varying speed, a fast commutation error correction method is proposed in this article. First, it is pointed out that the controlled variable variation, the high rate of commutation error relative to the low speed and the nonlinearity of the correction loop are the main origins of commutation error when the speed varies rapidly. Then, a novel commutation error correction method is proposed through the following three aspects: first, constructing a controlled variable first utilized for commutation correction, which keeps constant at the rapidly varying speed; second, incorporating feedforward compensation for the phase shift caused by low-pass filter; third, using feedback linearization to reduce the nonlinearity of the correction loop. The proposed commutation error correction method not only corrects the commutation error fast at a constant speed, but also achieves precise commutation when the rotor speed changes rapidly. Moreover, the proposed method is based on the principle of closed-loop control, thus, it also has the advantage of anti-interference. At last, the experimental results are shown to validate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

There is an urgent need to develop a robust capacitor charge power supply (CCPS) system to meet the requirement of pulsed load in all‐weather mobile occasions such as vehicle, ship and aircraft. Brushless doubly fed alternator (BDFA) works through the rotor's pole pairs' transformation to get excitation indirectly, without magnets, brushes and slip rings. Both DC and AC excitation can be used. Therefore, it has high reliability and a good application prospect in the CCPS system. However, the existing research studies lack analysis of the parameters that affect charging performance, and have no experimental analysis of the prototype. To solve this problem, a comprehensive design method and experimental procedure of the pulsed BDFA are proposed and investigated. First, the operation principle of the pulsed BDFA is illustrated. Then, the charging performances under different design schemes are comparatively analysed through the finite element analysis (FEA). Finally, a prototype of the pulsed BDFA is manufactured, and the related experiments are carried out. The results verify the feasibility of the experimental procedure and the accuracy of FEA. The comprehensive design method and experimental procedure in this work provide a straightforward reference for the subsequent applications in the CCPS system. [ABSTRACT FROM AUTHOR]

The application of Hall-based BLDC motors ranges from automotive accessory components such as oil and water pumps to high speed compressors. This paper proposes a new twelve-step unsymmetrical 160° commutation strategy using a single Hall-effect sensor method for brushless DC (BLDC) motor drives. The signal from the Hall-effect sensor is used to generate a number of pseudo Hall signals via a proposed speed-position estimator. The pseudo signals are then employed to control switching logic of a voltage source inverter (VSI). The effectiveness of the single Hall sensor method is examined on the unconventional 160° strategy, and on conventional 120°, 150° and 180° strategies with promising results. The paper presents a detailed comparison of the twelve-step unsymmetrical 160° commutation strategy with six-step voltage space vector that is used in conventional 120° and 180° strategies, and twelve-step symmetrical voltage space vector that is used in 150° strategy. Simulation results are validated via experimental measurements on a laboratory set-up using a real time dSPACE control environment, a representative BLDC motor prototype, a VSI and associated control components. [ABSTRACT FROM AUTHOR]

Brushless structure is beneficial for air-core compensated pulsed alternator (ACPA) because its field current and rotation speed are too large for the slip rings and carbon brushes. To achieve the brushless structure, a cascaded brushless self-excited ACPA (CBSACPA), which consists of an exciter and a generator in cascade, is proposed, in this article. The exciter and generator have a common rotor. A novel squirrel-cage rotor winding (SCRW), which can eliminate the end winding compared with conventional wound rotor winding (WRW), is proposed to simplify the rotor structure and improve the performance. First, the structure of the CBSACPA with the SCRW is introduced. Second, the operation principles of the machine are elaborated. Third, the dynamic mathematical model is presented. Fourth, the operation principles are demonstrated by the finite-element method. In addition, the performance of the SCRW is compared with the WRW as well. Finally, a prototype of CBSACPA is developed and tested to validate the analyses and simulations. In conclusion, this study gives detailed introduction, analyses, and validation about the CBSACPA, which provides a new solution to achieve a brushless structure for the ACPA. [ABSTRACT FROM AUTHOR]

This study presents a study of fault‐tolerant operation for a brushless doubly fed reluctance generator (BDFRG) system under a converter switch fault. The topology of the dual converter fed open‐winding BDFRG is adopted to improve post‐fault operation capacity. For post‐fault operation, the appropriate voltage vectors of control winding are selected to directly adjust the active and reactive power of power winding based on the direct power control theory. Switching tables are formulated under different switch faults. The simulation and experimental results demonstrate the feasibility of the proposed strategy. [ABSTRACT FROM AUTHOR]

This study compares the properties of dual‐channel brushless DC motors with permanent magnets (DCBLDCMs) in three configurations of the stator windings of both channels. An analysis was performed of star‐connected (Y), delta‐connected (Δ), and combined star–delta (YΔ) channel windings. A proprietary mathematical model of a DCBLDCM machine with combined star–delta windings is presented. Each type of winding configuration was evaluated in terms of tolerance to the occurrence of a discontinuity in the channel. An Fast Fourier Transform (FFT) analysis of the selected voltage signal was used to diagnose the operating status of the DCBLDCM. It was demonstrated that it provides unambiguous information about the operating status of individual channels of the motor. In the case od 24/10 DCBLDCM design, the harmonic spectra of a selected voltage signal in relation to the artificial neutral point, are presented. The results of simulation tests were compared with the results of laboratory measurements. It was demonstrated that an FFT analysis of a voltage signal in relation to the artificial neutral point identifies a fault in a channel of the motor. When evaluating the characteristics of individual winding configurations, the value of electromagnetic torque, torque ripple, system efficiency, and emitted noise were taken into account. In the conclusions, the advantages of the combined star–delta winding compared to the traditional star and delta winding configurations are presented. [ABSTRACT FROM AUTHOR]

Performance enhancement of a powertrain DC–DC converter is provided using a current‐controlled magnetic device, the variable inductor (VI). The VI is composed of two groups of windings, main and auxiliary. The auxiliary winding is used to regulate the permeability of the magnetic core over a wide range of load variations. To regulate the saturation level of the magnetic core and avoid postsaturation operation of the power inductor, an appropriate level of auxiliary winding current is needed. To this end, a simple and dynamic strategy is proposed to estimate the auxiliary winding currents of the VI. The proposed approach is validated using simulation studies of a large‐scale VI‐based powertrain DC–DC converter. The results reveal the significance of the proposed approach in continuous regulation of the magnetic property of the power inductor core, enhancing powertrain DC–DC converter performance by up to 13.70% and reducing stress on switching devices by 17.87%. Furthermore, energy source current variation is reduced by 6.73%, leading to reduced stress on energy storage systems. [ABSTRACT FROM AUTHOR]

This article presents a potential wind energy conversion system (WECS) using the recently proposed brushless induction excited synchronous generator (BINSYG), which can operate as a self-excited synchronous-machine. In BINSYG, an induction-machine (IM) and a synchronous-machine (SM) are wound for different number of poles and are embedded in the same machine structure. By operating the SM in self-excited mode, dc-link voltage of grid-side inverter can be controlled smoothly from the stator side of the IM. A set of conditions has to be maintained for stable operation in self-excited mode. This is particularly critical when the machine needs to be operated in wide variation in speed. So far, no stability-study is available to explore the stable-operating-zone, when the machine operates in self-excited mode. Therefore, in this paper stability of self-excited BINSYG is investigated to check suitability of the proposed system for wind energy applications. The study clearly indicates the presence of a critical speed (i.e. a minimum speed below which self-excitation is not possible). The movement of eigen values are presented to show the influence of several parameters on stable behavior of the system. Simulations using PLECS and supporting experimental-results using a laboratory-prototype (configured for 4/6 poles, 5.5 kVA) have been presented. [ABSTRACT FROM AUTHOR]

This article proposes an optimized direct instantaneous torque control (DITC) scheme for switched reluctance motor (SRM) drives with a novel adaptive dynamic commutation strategy, which can effectively reduce torque ripple and improve system efficiency. To minimize torque ripple, two operational modes are developed for torque tracking during commutation regions. In Mode I, the torque error is compensated by the outgoing phase during the current buildup region of the incoming phase; in Mode II, the torque error is compensated by the incoming phase during the demagnetization region of the outgoing phase. To implement the proposed DITC scheme in a more effective conduction range, the commutation instants are dynamically adjusted according to the varied operation conditions. For each phase, the turn-on and turn-off angles are modified in each electrical cycle by a torque error regulator and a phase current endpoint detector, respectively. By employing the proposed strategy, the torque generation capability is fully utilized for minimized torque ripple, and the phase currents work within a more effective conduction range for improved system efficiency. The simulation and experiments on a three-phase 12/8 SRM are carried out to verify the feasibility and effectiveness. [ABSTRACT FROM AUTHOR]