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Home appliances such as residential air conditioners are based on the variable speed drives for AC motors such as IPMSM and IM. These variable speed drives always require the simple and low‐cost system configurations without the large electrolytic capacitors, reactors, and power devices that consist of PFC converters. This paper surveys and analyzes the proposed and advanced control techniques to achieve high input power factor and sinusoidal source current control in electrolytic capacitor‐less inverters. The investigated control methods consist of control algorithms based on the energy flow between input and output of the electrolytic capacitor‐less inverter, and all of them are useful as high‐power factor control methods for compressor drive motors such as air conditioners. Moreover, these techniques realize the variable speed drives for AC motors to meet power supply harmonics regulations (IEC61000‐3‐2). © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

In the actual production process of oil fields, the real-time and accurate acquisition of dynamic recorder data from the pumping unit is of great significance for the diagnosis of well failures. The traditional method of obtaining the card of the dynamometer usually includes installing a load sensor on the auxiliary head of the pumping unit. However, due to the harsh environment of the oil field production site, these load sensors often suffer from damage, distortion, and aging, resulting in large measurement errors and low reliability. This paper proposes a mixed model of pumping based on motor electrical parameter data and CNN convolutional neural network, which has good consistency with actual data in terms of predictive performance. Thus, the highlights of this paper can be summed up in two points: (1) Based on the mathematical model of the AC motor, the speed of the motor and the torque output of the motor are accurately estimated. (2) The convolutional neural network is introduced to compensate for the errors caused by the defects of the pumping unit mechanism model. [ABSTRACT FROM AUTHOR]

The authors present the multi‐physical field performances comparative research for a 30 kW, 30,000 r/min high‐speed permanent magnet motor (HSPMM) when the motor is powered by the sinusoidal pulse width modulation (SPWM) voltage inverter and sinusoidal voltage source, respectively. Firstly, electromagnetic performances including torque, voltage and current of the HSPMM with different driving methods are compared and analysed by the finite element method (FEM). Considering the effects of high operation frequency, power losses of the HSPMM with different driving methods under full‐load conditions are calculated and compared with the skin effect and the proximity effect considered for HSPMM winding copper loss estimation. Based on the above analysis, a prototype driven by the SPWM voltage inverter is manufactured, with its electromagnetic and thermal performances tested and verified. In addition, several influencing factors of the HSPMM rotor eddy current loss are studied, with their effects on the HSPMM under different driving methods further analysed and compared as well. A novel equivalent power supply method is proposed to effectively save the calculation time with a negligible error. Finally, in order to further improve the heat dissipation capacity of the HSPMM, a novel cooling method is intensively studied with its influencing factors further analysed. The cooling effect of the novel cooling method and the temperature of the motor components are verified and calculated by the computational fluid dynamics (CFD) method. [ABSTRACT FROM AUTHOR]

Machine acoustics is an important area of research impacting the quality and comfort of human life. With increased levels of electrification and the wider use of electric motors, the contribution of motor drives towards quieter acoustic systems becomes increasingly important. This paper presents a novel acoustic improvement method involving the use of acoustic waves generated from High Frequency Injection to perform Active Noise Control. Although High Frequency Injection has been used widely in the domain of sensorless motor control, its acoustic generation process has been so far perceived as a negative by‐product. This paper presents the analysis and experimental results from the application of the proposed method to the Helicopter Electro‐Mechanical Actuation System. Considering the extensive use of motor drives in a number of industries, the proposed practice of High Frequency Injection Active Noise Control can have a significant impact to future applications. [ABSTRACT FROM AUTHOR]

In order to address the issues of complexity, high cost, large volume, and low reliability associated with traditional H‐bridge cascaded converters when operating under high voltage, high capacity, and dual electric motor loads, the authors propose the utilisation of a nine‐switch converter as an alternative to the conventional H‐bridge converter for implementing cascaded multilevel converters in dual electric motor drive systems. After conducting an analysis and research on the topology and operational control strategy of cascaded multilevel converters based on the nine‐switch converter, a design is presented using six individual nine‐switch converter units to develop a cascaded multilevel converter capable of driving two 3 MW asynchronous electric motors at a 6 kV voltage level. Simulation verification is performed, and a scaled‐down prototype is built for experimental validation. The results demonstrate that, in comparison to traditional H‐bridge cascaded converters, the proposed cascaded multilevel converter can effectively drive dual electric motors at the same or different frequencies while reducing the number of switches to 1/4, the total transformer windings to 1/2, and Direct Current‐side capacitors to 1/6. This improvement enhances system reliability, portability, and load adaptability, thus offering increased versatility in dual electric motor drive applications. [ABSTRACT FROM AUTHOR]

Electrical and mechanical subsystems are the main parts of the powertrain of an Electric Vehicle (EV). These parts include principally electric motors, inverters, batteries, wheels, axles, differentials, and transmissions. Permanent Magnet Synchronous Motor (PMSM) is one of the most popular used motors in the electric powertrain due to its several benefits over other AC motors, such as its small size, low weight, wide range of speed, elevated overload capacity, elevated power factor, and elevated efficiency. This paper compares the performance of PI and sliding-mode controllers for PMSM employed in electric vehicle applications with single-motor drive configurations. Dynamic performance and robustness are the main topics of the comparative analysis. The robustness of the drive train with sliding-mode controller is proven by simulation results. [ABSTRACT FROM AUTHOR]

Currently, excessive AC loss in the rectangular winding motor used for electric vehicles poses a significant challenge, necessitating effective measures to suppress the losses. This paper focuses on the Prius IV motor, employing a finite element two-dimensional model established using JMAG software. The influence of conductor material and the number of rectangular winding layers on motor AC loss under various operating conditions is thoroughly analyzed. Maintaining a constant number of rectangular winding layers, aluminum (Al) conductors replace copper (Cu) conductors in 2-layer, 4-layer, 6-layer, and 8-layer configurations, respectively. AC losses are compared among motors with 4-layer, 6-layer, 8-layer, and 10-layer Cu rectangular windings, all having identical slot dimensions. Subsequently, the 10-layer Al conductor scheme is chosen to optimize motor design. The results demonstrate an average reduction in AC loss up to 59.24% after motor optimization, further reducing motor manufacturing costs. [ABSTRACT FROM AUTHOR]

Featured Application: This paper proposes a method of monitoring the condition of three-phase asynchronous induction motors running with no load based on computer analysis of the instantaneous active electrical power. This paper experimentally reveals some of the resources offered by the instantaneous active electric power in describing the state of three-phase AC induction asynchronous electric motors (with a squirrel-cage rotor) operating under no-load conditions. A mechanical power is required to rotate the rotor with no load, and this mechanical power is satisfactorily reflected in the constant and variable part of instantaneous active electric power. The variable part of this electrical power should necessarily have a periodic component with the same period as the period of rotation of the rotor. This paper proposes a procedure for extracting this periodic component description (as a pattern by means of a selective averaging of instantaneous active electrical power) and analysis. The time origin of this pattern is defined by the time of a selected first passage through the origin of an angular marker placed on the rotor, detectable by a proximity sensor (e.g., a laser sensor). The usefulness of the pattern in describing the state of the motor rotor has been demonstrated by several simple experiments, which show that a slight change in the no-load running conditions of the motor (e.g., by placing a dynamically unbalanced mass on the rotor) has clear effects in changing the shape of the pattern. [ABSTRACT FROM AUTHOR]

The paper carries out the research on a novel two‐level voltage source inverter to further improve the output power quality of the inverter under the premise of efficient operation. Main switches can realize zero‐voltage switching in a wide load range to ensure the efficient operation of the designed inverter. Total harmonic distortion (THD) of the output current at low output frequencies can be improved by the modification of resonant tanks in the designed inverter. In the dead time, the modified resonant tanks can result in a shorter duration of nonlinear changes in the output phase voltage at lower load current, which is beneficial for reducing the output voltage error caused by dead time. The improved power quality at low output frequencies is conductive to the use of the designed inverter in the drive system of the low‐speed AC motor. The paper expounds every operating status during a switching period. The experiment manifests that switches realize soft switching. The efficiency of the designed inverter reaches 98.6% at rated operation state, which is 0.3% and 0.5% more than that of two comparison objects, respectively. Moreover, when the output frequency reduces to 5 Hz, the THD of the output current is only 2%, which is also less than that of comparison objects. Hence, the designed inverter has advantages in the efficiency and the output power quality. [ABSTRACT FROM AUTHOR]

This paper presents a review of the most common power converters and torque ripple minimisation approaches for switched reluctance motors (SRMs). Unlike conventional three-phase AC motors, namely squirrel cage induction motors and permanent magnet synchronous motors, which require a typical three-phase inverter for operation, the switched reluctance motor requires a different topology power converter for reliable and efficient operation. In addition, due to the non-linear, discrete nature of SRM torque production, torque ripple is severely pronounced, which is undesirable in servo applications like electric vehicles. Hence, deploying a proper torque control function for smooth and quiet motor operation is crucial. This paper sheds light over the most popular SRM power converters as well as torque ripple minimisation methods, and it suggests an optimal SRM drive topology for EV applications. [ABSTRACT FROM AUTHOR]

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Precise electromagnetic transient simulation of induction motors (IMs) under voltage sag condition is necessary in Electro‐Magnetic Transient Programme. Although traditional fifth‐order model can accurately reflect the electromagnetic transient behaviour of IMs, the disadvantage of massive computation limits its application in the large‐scale system simulation. Considering voltage sag is a typical power quality issue, a novel reduced‐order electromagnetic transient model based on equivalent flux linkage derivative is proposed to shorten simulation time during voltage sag. When characteristic parameters of voltage sag are given, an equivalent flux linkage derivative can be obtained simply, and the proposed model can effectively shorten the simulation time while ensuring accuracy of the fifth‐order model. Simulation results of small capacity (5.5‐kW) and large capacity (315‐kW and 1600‐kW) IMs in simple system and IEEE 9‐bus system confirm the applicability of the proposed model. It is estimated that simulation time of the proposed model decreases by 76% compared with the fifth‐order model. Finally, the experimental validation with the 5.5‐kW IM is carried out to show the effectiveness of the theory. [ABSTRACT FROM AUTHOR]

Summary: In a unidirectional five‐level ac motor drive system with open‐end winding connection, because of the variation of operating frequency of ac motor, the instantaneous power fluctuation of rectifier stage and inverter stage will generate larger voltage ripple on each phase dc‐link capacitors, and further lead to a large amount of current harmonics in output currents of inverter. To cope with this problem, an improved space vector pulse width modulation (SVPWM) strategy based on dc‐link voltage feedforward is proposed. In this paper, the effects of zero sequence current harmonics caused by dc‐link voltage ripple on ac motor are firstly analyzed, including the stator winding flux linkage equation, voltage equation, and electromagnetic torque. Then, the generating mechanism of dc‐link voltage ripple and the current harmonics are discussed in detail in terms of instantaneous power fluctuation of each single‐phase converter. Based on this, an improved SVPWM strategy by modifying the modulation signal is proposed to suppress the generation of current harmonics. Finally, a 2.2 kW prototype experimental results are given, which verify the feasibility and advancement of the proposed modulation strategy. [ABSTRACT FROM AUTHOR]

The direct torque control (DTC) strategy was proposed more than 25 years ago. It is one of the most successful and reliable techniques for AC motors. This paper presents the application of DTC using a four-switch inverter, as one of the non-conventional economic topologies suitable for low power ranges. The experimental prototype proves the validity and effectiveness of the investigated configuration. In addition, for comparison purposes, the DTC technique has been implemented using a conventional six-switch inverter. According to the experimental results, the DTC-based four-switch inverter would be competitive with the conventional topology in low power ranges to achieve an economic AC drive with a satisfactory transient and steady-state performance at moderate costs. [ABSTRACT FROM AUTHOR]

An H-bridge inverter with LC (inductor-capacitor) filter output allows the conversion of DC (direct current) power to AC (alternating current) power that has been used in a variety of applications, such as uninterruptible power supplies, AC motor drives, and renewable energy source systems. The fast finite-time sliding mode control (FFTSMC) features acceleration of the system state towards the equilibrium position as well as conserving insensitivity against internal parameter fluctuations as well as external load disturbances falling within the predetermined bounds. However, the FFTSMC would potentially witness chattering or steady-state errors as indefinite margins come to be exaggerated or underestimated. The chattering in the sliding mode control practice is oscillatory defective behavior. It induces inefficient operation, higher switching power losses in the transistor circuits, as well as saturated actuators, thus impairing the inverter's output energy efficiency and raising harmonic distortion. Therefore, this paper presents the H-bridge inverter with LC filter output, which is controlled by a grey prediction fast finite-time sliding mode trajectory tracking. A more highly accurate grey prediction model based on the centered approximation methodology is deployed to vanish the chattering as well as steady-state errors. Taking into account the union of grey prediction and FFTSMC, a feedback-controlled H-bridge inverter with LC filter output allows attaining a highly efficient as well as quality sine-wave output voltage. The presented state-feedback control strategy is robust, less complex, attains more rapid convergence, and is highly accurate. The design process, computer simulation, as well as experimental results of the proposed state-feedback control strategy established that the H-bridge inverter with LC filter output has the capability to exhibit fast dynamic response time as well as good steady-state tracking behavior of the output voltage under step-loading changes and nonlinear loading conditions. [ABSTRACT FROM AUTHOR]

In ultra‐high speed (UHS) motor applications, full SIC two‐level (2L) inverters with high switching frequencies are generally used due to their lower cost. However, even with the usage of all WBG power devices, high‐frequency hard‐switched 2L inverters still do not achieve optimal efficiency characteristics. As a result, in order to simultaneously reduce the switching frequency and enhance overall efficiency, recently three‐level (3L) topologies have emerged as a promising solution. Nevertheless, to fully meet the requirements of UHS applications, the switching frequency of 3L inverters should be increased beyond 30 kHz, which necessitates the usage of all SIC power devices. This, in turn, leads to a potential drawback where the cost of the drive system may become prohibitively high due to the requirement of all SIC switches. To address this issue and reduce the cost of a full SIC 3L inverter, a new 3L simplified sparse NPC (SSNPC) topology is proposed in this work. The operational principle of this topology, its distinctive control features, and the advantages it offers specifically for UHS applications are presented. Additionally, to further increase the efficiency and reduce the influence of dead time at low speeds, a new switching sequence is introduced. Finally, the overall performance and efficiency characteristics of the high‐frequency SSNPC inverter were verified across all operational conditions of UHS motor drive system. [ABSTRACT FROM AUTHOR]

In this study, we propose an implementation method of the Encoder Data (EnDat) interface master for slave encoders using only a configurable logic block (CLB) and a serial peripheral interface (SPI) integrated into microcontroller units. By programming the CLB device to execute logic functions and finite state machines designed for the EnDat interface master operation, we realize the EnDat and SPI clocks that are required for the EnDat interface master operation. This approach is cost-efficient because additional hardware components, such as a field-programmable gate array or a complex programmable logic device, are unnecessary for the master implementation. We build a one-axis feed drive system that is powered by an AC motor and equipped with an EnDat linear encoder for measuring table speed and position. By performing various experiments for table position and speed control based on the built feed drive system, we verify the performance and practical usefulness of the implemented EnDat interface master. The maximum EnDat clock frequency without the propagation delay compensation is achieved by 2 MHz, which can cope with 16 kHz control cycle frequency. The usefulness is demonstrated by showing the table speed and position control performance that are acceptable in real applications. [ABSTRACT FROM AUTHOR]

The Fourth Industrial Revolution has had a huge impact on manufacturing processes and products. With rapidly growing technology, new solutions are being implemented in the field of digital representations of a physical product. This approach can provide benefits in terms of cost and testing time savings. In order to test and reflect the operation of an electric car, a digital twin model was designed. The paper collects all the information and standards necessary to transform the idea into a real and virtual model of an electric car. The significance and impact of the study on the improvement of the project are described. The research stand, correlations of components (DC and AC motors, shaft, and wheel of the electric car), and development prospects are presented in the paper. The communication method with the research stand is also presented. The digital twin should communicate in real time, which means obtaining the correct output when the input changes; the input is the AC motor current, and the output is the rotational speed of the DC motor. The relation between inputs and outputs are tested. The kinematics of the electric car are modelled in LabVIEW. The results obtained are compared with historic racing data. The track is also modeled based on satellite data, taking into account changes in terrain height, using the SG Telemetry Viewer application. The parameters of the electric car engine model are tuned based on actual data on the car's speed and current in the electric motor. The achieved results are presented and then discussed. [ABSTRACT FROM AUTHOR]

Safety and reliability are very important in machine driving systems for many industries. A novel rotor flux‐based Vector Control (VC) strategy for Y‐connected 3φ Induction Machines (IMs) without speed sensor under the Single‐Phase Fault (SPF) is proposed. The sensorless VC technique is based on using Asymmetrical Transformation Matrices (ATMs) for stator voltage and current components as well as an Extended Kalman Filter (EKF) for estimation of the speed and d‐q fluxes. Furthermore, a simple model‐based SPF detection mechanism based on the EKF is suggested. The performance of the proposed control scheme for a 1 HP sensorless Y‐connected 3φ IM prototype is validated by several experiments. According to the experimental results, the designed scheme during the SPF has several advantages of improved phase currents and low speed, flux, and torque ripples. [ABSTRACT FROM AUTHOR]

A stacked polyphase bridge converter consists of multiple standard, three‐phase two‐level voltage source inverters connected in series to the same dc voltage source. The authors present a decentralised and dynamic dc‐bus reconfiguration strategy for this type of converter. The innovation of the proposed strategy lies in its ability to isolate or reactivate one of the inverters in the series connection online, even in motoring mode, enabling increased fault tolerance and an extended speed range. Both the required hardware alterations and the multi‐agent control strategy are addressed. Its major benefits compared to the state‐of‐the‐art are that only two additional active, unidirectional semiconductor switches are required per inverter, and that the control is based on local computations, local measurements and neighbour‐to‐neighbour communication only. Hence, the scalability and reliability of the hardware are extended towards the control. Simulations and experimental results on a 4 kW modular axial‐flux PMSM prove the feasibility of the concept, and validate that the dc‐bus can be reconfigured in 100 ms, without torque interruption. [ABSTRACT FROM AUTHOR]

Induction motors (IMs) are one of the most widely used motor types in the industry due to their low cost, high reliability, and efficiency. Nevertheless, like other types of AC motors, they are prone to various faults. In this article, a low-cost embedded system based on a microcontroller with the ARM Cortex-M4 core is proposed for the extraction of stator winding faults (interturn short circuits) and an unbalanced supply voltage of the induction motor drive. The voltage induced in the measurement coil by the axial flux was used as a source of diagnostic information. The process of signal measurement, acquisition, and processing using a cost-optimized embedded system (NUCLEO-L476RG), with the potential for industrial deployment, is described in detail. In addition, the analysis of the possibility of distinguishing between interturn short circuits and unbalanced supply voltage was carried out. The effect of motor operating conditions and fault severity on the symptom extraction process was also studied. The results of the experimental research conducted on a 1.5 kW IM confirmed the effectiveness of the developed embedded system in the extraction of these types of faults. [ABSTRACT FROM AUTHOR]

A simple control structure with high anti‐disturbance ability is proposed here for permanent magnet synchronous motor (PMSM) drives. The conventional cascade structure, with an outer speed loop and an inner current loop, is simplified and merged into one single‐loop controller. To enhance the dynamic performance and efficiency of the PMSM drives, an enhanced adaptive reaching law (EARL) is proposed for the single‐loop control strategy. In comparison with conventional reaching laws, the EARL can increase the convergence speed, adapt the gain to fit the system state, and reject the chattering phenomena of conventional sliding mode control. Moreover, an improved disturbance observer (DOBS) is developed to work with the main controller. The DOBS aims to enhance the estimation accuracy of real‐time unknown disturbances in the PMSM system, thereby further improving the disturbance rejection capability through feedforward compensation for the single‐loop control strategy. The EARL and DOBS thus enhance the robustness of the control strategy and ensure high dynamic performance at various motor operating conditions. The performance and efficiency of the proposed control are validated through simulations and experimental studies. [ABSTRACT FROM AUTHOR]

The proposed research addresses the optimization challenges in servo motor control for pipe-cutting machines, aiming to enhance performance and efficiency. Recognizing the existing limitations in parameter optimization and system behavior prediction, a novel hybrid approach is introduced. The methodology combines a Dandelion optimizer algorithm (DOA) for servo motor parameter optimization and an Attention pyramid convolution neural network (APCNN) (APCNN) for system behavior prediction. Integrated with a Programmable Logic Controller (PLC) and humanmachine interface (HMI), this approach offers a comprehensive solution. Our research identifies a significant research gap in the efficiency of existing methods, emphasizing the need for improved control parameter optimization and system behavior prediction for cost reduction and enhanced efficiency. Through implementation on the MATLAB platform, the proposed DOA-APCNN approach demonstrates a noteworthy 30% reduction in computation time compared to existing methods such as Heap-based optimizer (HBO), Cuckoo Search Algorithm (CSA), and Salp Swarm Algorithm (SSA). These findings pave the way for faster and more efficient pipe-cutting operations, contributing to advancements in industrial automation and control systems. [ABSTRACT FROM AUTHOR]

An AC excitation power supply will produce a series of harmonic currents in motors compared to the conventional power supply, increase the time harmonic component, and then generate a harmonic magnetic field; harmonics will cause motor vibrations and noise in the motor and will produce a corresponding additional loss, increasing the motor temperature rise; these key technical problems need to be solved in domestic pumped storage AC excitation motor engineering applications. Herein, the no-load loss characteristic test of a 3 MW alternating current excited motor was mainly carried out using a test prototype of the 3 MW alternating current excitation motor. Further, with the aid of the finite element method, the numerical study of the no-load loss characteristics of a 3 MW alternating current excited motor was performed. The relationship between the key factors such as the no-load characteristics, no-load loss characteristics, and constant loss and voltage per unit value is analyzed, and the variation law of the no-load core loss of motors under different loads is explored. The results demonstrate that, under no-load conditions, when the applied voltage was less than the rated voltage, the voltage was proportional to the current. When the applied voltage was more significant than the rated voltage, the current increased as the voltage increased, but the relationship between the two was no longer proportional. The constant loss of the motor maintained a linear relationship with the square of the unit value of the voltage scale. When the square of the unit value of the voltage scale was zero, the loss was equivalent to the wind friction loss under no load. The core loss increased with the increase in load, and the greater the load, the faster the increase rate of the motor iron loss. The comparison deviation between the test and simulation results was less than 10%. The simulation and experimental results verified the effectiveness of finite element modeling and the finite element calculation method. [ABSTRACT FROM AUTHOR]

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The rapid adoption of electric vehicles (EVs) has driven the industry to develop advanced traction systems for improved performance and dependability. Such criteria are determined mainly by the magnetic materials used in brushless DC or AC motor commonly used in EV traction systems. More complex motor designs, such as those with two rotors or two stators, have been influenced by improvements in traction systems for transportation tools. The electric motor with multiple rotors or stators has a complex system and lies on parameters that change over time with complex dynamics. Consequently, this motor type needs an intelligent controller to enhance its efficiency and robustness under various drive conditions. Therefore, this article aims to resolve some control complexity for one of these recently used motors. The goal of this is to maximize the efficiency while also increasing motor torque. This motor design is based on a double-stator single-rotor (DSSR) form. The global traction chain is described in this paper by showing the specifications of each part as the interior motor architecture and a suitable AC/DC converter. Examining the best control tool for managing this machine is based on the control topology by using on the field-oriented control (FOC) strategy. A comparison of the effects of three distinct speed controllers, including fuzzy logic, neural networks, and traditional PI controllers, was used to support the FOC architecture. The global traction system architecture and its corresponding control scheme were established on the MATLAB/Simulink platform, and all results were depicted to compare the diverse architectures. At the end of this study, the given results and their corresponding discussions show each control solution's benefits and drawbacks and prove the importance of choosing the appropriate control system for the DSSR motor on the battery state of charge and then on the vehicle autonomy. [ABSTRACT FROM AUTHOR]

Constant switching frequency pulse width modulation (PWM) schemes introduce harmonics in the inverter's output voltage and current which are concentrated at frequencies close to the switching frequency and its multiples. This peaking in the current and voltage harmonic spectrum results in vibration and acoustic noise in AC motor drives. One way to alleviate these problems is by spreading the harmonic spectrum and reducing the magnitude of dominant harmonic components using variable switching frequency schemes. The key objective of this paper is to introduce a novel trapezoidal variation based variable frequency PWM switching strategy to spread out the harmonic spectrum, with reduced current THD even during no-load low-speed operation. This paper also proposes a modified switched DC cell inverter to achieve DC voltage control to enhance the THD reduction. The presented strategy achieves a maximum of 42.2 % reduction in low-speed THD compared to linear sub-cycle period variable frequency PWM, a 46 % reduction in dominant harmonics compared to conventional space vector PWM, and a dispersion index of 1.61, demonstrating its competency as a promising variable switching frequency scheme. The suggested techniques are simulated using MATLAB/Simulink on a vector-controlled Permanent Magnet Synchronous Motor (PMSM) drive and are validated experimentally on a 1.07 kW PMSM drive with a WAVECT-FPGA controller. [ABSTRACT FROM AUTHOR]

Recently, the three-phase induction motor (IM) has been widely used in AC motor drives and in industrial applications. The IM suffers from the accuracy of controlling the speed when it operates at different loads; this problem attracts the attention of many researchers in this field. This paper presents an Intelligent Hybrid Control System using ANFIS (Adaptive Neuro-Fuzzy Inference System)-Optimization for Scalar Control (SC) of an Induction Motor. In order to obtain optimum performance of the motor and to decrease the Total Harmonics Distortion (THD) of the motor current a Voltage Source Inverter (VSI) based on the Pulse Width Modulation technique (PWM) is used to drive the motor. To improve the speed response, accuracy and the motor's performance, an improved hybrid control system involves an optimization control method in addition to an Adaptive Neuro-Fuzzy Inference System used to adjust the amplitude and the Modulation Index (MI) of the reference signal. The proposed hybrid system improves the transient stability of motor speed and reaches a steady state much faster than the traditional controller. The Matlab-Simulink results proved the remarkable effectiveness of the proposed controller when comparing the results with two other controllers, the usual PI controller and the optimization controller. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The application of electrical drives in the control of centrifugal fans and pumps is a well-established area that leads to substantial energy savings. It requires electrical and automation engineers to have some knowledge relevant to drives about fan and pump modelling since ignoring or oversimplifying fan/pump modelling for the intended drive design compromises the required control quality. This paper improves the existing dynamical models of fans and pumps integrated with induction motors via neural network estimation of overall fan/pump efficiency; this estimation is based on the voltage frequency of the driving induction motor, pressure, and flow rate, followed by the separation of the fan's or pump's own efficiency for the motor load torque computation, enhancing the accuracy due to the correct reflection of the power balance. The model is developed with a view to being convenient for control design applications. For the first time for dynamical models, it is verified experimentally, justifying the necessity of the first-order nonlinear differential equation for the flow rate. The validation includes a direct approach based on analysis of transient behaviour caused by a small-step perturbation of the frequency of the motor voltages and an indirect approach based on the introduced concept of the dynamical flow rate and pressure estimators. [ABSTRACT FROM AUTHOR]

In order to ensure the high precision and good dynamic characteristics of the dual‐axis linear motor when machining components, the tracking error and contour error should be reduced with more complex machining trajectory. In this study, the characteristic model of position control of the linear motor is established by using the modelling principle of the characteristic model, and the intelligent adaptive controller is designed. In addition, a new calculation method of the equivalent contour error is proposed innovatively, and the dual axis is compensated by proportional feedback control, to improve the contour accuracy of the permanent magnet synchronous linear motor dual‐axis control system. Finally, through the simulation and experiment of the dual‐axis motor platform, the effectiveness of the proposed contour error calculation method and the intelligent adaptive controller can make the dual‐axis motion control system have higher accuracy and strong robustness and can also make the motor run more smoothly. [ABSTRACT FROM AUTHOR]

To solve the problems mechanically caused by parallel direct‐drive permanent magnet motors (DD‐PMSM). This paper proposes a concave‐core stator direct‐drive permanent magnet motor (CCSDD‐PMSM) structure. In this study, an auxiliary yoke structure is proposed to optimise the magnetic circuit and analyse the cogging torque to achieve the minimum detent force. Based on the unit motor and combined with the magnetomotive force to analyse the symmetry of different winding distributions, the stability characteristics of the motor are studied. The magnetic field distribution of the motor load air gap is calculated using the finite element method. The contribution of different spatial order harmonics to the motor output torque is calculated using the Maxwell tensor method. The torque calculation expression of the CCSDD‐PMSM is given. Finally, an experimental prototype is made to verify the accuracy of the analysis in this paper. [ABSTRACT FROM AUTHOR]

This article presents a comprehensive review of reduced device count multilevel inverter (RDC MLI) topologies for PV systems. Multilevel inverters are widely used in medium-voltage and high-power applications such as wireless power transform applications, flexible AC transmission (FACT), active filters, AC motor drives, high-voltage DC transmission (HVDC), and renewable energy sources due to their high modularity and high-power quality output. Multilevel inverters have the ability to diminish the harmonics content in the output voltage by applying various modulation techniques. The literature in this field showed that the high-power quality and high modularity of the output demand an undeniable need for multilevel inverter topology. Research in this field has identified various multilevel inverter topologies, each possessing their own merits and demerits. The ubiquitous availability of multilevel inverter topologies illustrates the complexity of their accurate selection. To avoid such complexity, this review shows the state of the art of various reduced device count (RDC) multilevel inverter (MLI) topologies. Details of the various RDC MLIs, along with their comparisons, are provided in this paper. This review will be an important reference tool for future work on RDC MLI for photovoltaic (PV) systems. [ABSTRACT FROM AUTHOR]

Condition monitoring in electric motor drives is essential for operation continuity. This article provides a review of fault detection and diagnosis (FDD) methods for electric motor drives. It first covers various types of faults, their mechanisms, and approaches to detect and diagnose them. The article categorizes faults into machine faults, power electronics (PE) faults, DC link capacitor faults, and sensor faults, and discusses FDD methods. FDD methods for machines are categorized as statistical methods, machine-learning methods, and deep-learning methods. PE FDD methods are divided into logic-based, residual-based, and controller-aided methods. DC link capacitor and sensor faults are briefly explained. Machine and PE faults are listed and presented as tables for easy comparison and fast referencing. Most papers are selected from the past five years but older references are added when necessary. Finally, a discussion section is added to reflect on current trends and possible future research areas. [ABSTRACT FROM AUTHOR]

Inverters are DC to AC power converters that are widely used in AC motor drives and distributed energy generation systems. Multi-Level Inverters (MLIs) have emerged as the preferred inverter technology because of their advantages of reduced switching losses and better harmonic profile. This paper deals with the Minimization of Total Harmonic Distortion (MTHD) of Symmetric Cascaded H-bridge Multi-Level Inverter (SCMLI) and Asymmetric Cascaded H-bridge Multi-Level Inverter (ACMLI). A hybrid memetic algorithm composed of heuristic PSO (Particle Swarm Optimization) algorithm and traditional MAS (Mesh Adaptive direct Search) is proposed to optimize the switching angles. In Photo Voltaic (PV) system, the input DC voltage generally varies from its nominal value due to the change in temperature and irradiance. Thus, the sensitivity analysis of THD and harmonics is also carried out considering the variations with non-integer magnitudes of input DC sources. The experimental prototype of SCMLI and ACMLI topology is developed and validated with simulation results. The reliability and Mean Time to Failure (MTTF) of SCMLI and ACMLI are investigated based on power losses of the MOSFET and thermal parameters. [ABSTRACT FROM AUTHOR]

The position sensorless permanent magnet synchronous motor (PMSM), with its simple structure, is applied in the aerospace field with high reliability requirements. To drive PMSM safely, the three‐phase current measured from the driver needs to be isolated for the closed‐loop control. And then, the accuracy current measurement is crucial for achieving optimal motor performance. In the paper, current transformer (CT) with centre taps is employed to isolate and measure the high‐frequency current of the inverter switch. Additionally, an algorithm is proposed to reconstruct the switch current into the low‐frequency phase current. Subsequently, the measuring method and the algorithm are applied to an inverter platform, which drives a 100W PMSM. Finally, the reconstructed phase current waveform is compared with the measured phase current waveform, and the experimental results show that the above method is effective and feasible. [ABSTRACT FROM AUTHOR]

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The design and optimisation of a permanent magnet‐assisted synchronous reluctance (PMaSynR) traction machine is described to improve its energy efficiency over a selection of driving cycles, when installed on a four‐wheel‐drive electrically powered vehicle for urban use, with two on‐board powertrains. The driving cycle‐based optimisation is defined with the objective of minimising motor energy loss under strict size constraints, while maintaining the peak torque and restricting the torque ripple. The key design parameters that exert the most significant influence on the selected performance indicators are identified through a parametric sensitivity analysis. The optimisation brings a motor design that is characterised by an energy loss reduction of 8.2% over the WLTP Class 2 driving cycle and 11.7% over the NEDC and Artemis Urban driving cycles, at the price of a 4.7% peak torque reduction with respect to the baseline machine. Additional analysis, implemented outside the optimisation framework, revealed that different coil turn adjustments would reduce the energy loss along the considered driving cycles. However, under realistic size constraints, the optimal design solutions are the same. [ABSTRACT FROM AUTHOR]

In this study, speed control of alternative current (AC) universal motor is made in a computerized manner using PIC16F84A and PIC18F2550. AC universal motor speed control is realized by triggering the motor power circuit, triac with the phase angle control method by programming PIC16F84A. In the phase angle control method zero crossing points of AC line signal are detected by zero crossing detector and applied to the analog input of PIC16F84A. Zero crossing information applied to the microcontroller has provided phase control at a desired angle value in each alternance of the line. Motor speed control commands via computer are made by means of the control panel designed under Visual Basic 6.0 platform by using PIC18F2550 microcontroller based control card. Application results show that the speed control performed provides practical and easy control, is convenient, sensitive, and economic and also can immediately be adapted to different applications compared to the present analog control. [ABSTRACT FROM AUTHOR]

The flat wire motor for Electric Vehicles have the characteristics of small size, light weight and high power density. However, with the development of high-speed motor, the AC loss of flat wire motor becomes larger, and its thermal rise performance is different from the traditional circular wire motor, so it is necessary to design a cooling method suitable for it. Firstly, a two-dimensional finite element model of a high speed flat permanent magnet synchronous motor for new energy vehicles was established, the influences of the size, layer number and parallel branches number of the flat conductor on the AC loss of the motor under the driving cycle of WLTC-3 were analyzed, and the optimal conductor size and winding connection mode were obtained. Then on the basis of loss analysis, according to the temperature field distribution of the motor, the optimal cooling method of oil cooling has been designed, which reduces the temperature rise and improves the reliability of the motor operation. [ABSTRACT FROM AUTHOR]

The past two decades have witnessed the development of finite-time stabilization as a hot spot in control area. Using the technique of finite-time stabilization, control system or observer can be designed such that the system error or estimation error converges to zero in finite time. This property is valuable for mission-critical systems with stringent time specification. This paper takes the permanent magnet synchronous AC motor, which has been widely used in industrial servo systems, as the target system for control. In the field-oriented framework, position servo controllers are designed for motor position-speed loop, using a combination of finite-time control law and finite-time observer. Comparison will be made with a conventional controller which only achieves asymptotic convergence. An experimental test-bench is established using a TMS320F28335 digital signal processor, and experiment results are presented to verify the effectiveness of the designs. The comprehensive experiments is adopted in the undergraduate module of computer control system practice and the graduate modules of control engineering, which can help students appreciate the potential of advanced control techniques, and inspire on them the desire for creativity. [ABSTRACT FROM AUTHOR]

By taking the spring mass damping system of the single degree of freedom excited by the eccentric rotor as the object， Sommerfeld effect of the non-ideal vibration system driven by the AC motor as the prime motor was studied. The electromagnetic torque formula of the AC motor was introduced to establish the dynamic model of the vibration system driven by the AC motor. Based on the small parameter averaging method， the approximate solution of the vibration system response was obtained. According to the solution， the torque balance equation of the motor in steady-state motion was derived. Numerical analysis illustrated that the angular velocity of the motor and the frequency of power will jump in the resonance region， and the relationship between the amplitude of the system and the frequency of power has hard non-linear characteristics. The mechanism of these phenomena was explained by the stability judgment conditions， and the correctness of the theoretical method was verified by the numerical time domain simulation. Finally， the key structural parameters were discussed quantitatively and qualitatively. [ABSTRACT FROM AUTHOR]

In this paper, an extended-horizon predictive torque control (PTC) method is proposed with computationally efficient implementation. Predictive control with extended horizon brings important advantages compared to single-horizon methods, such as better steady-state performance, reduced current THD, and lower ripples in torque and stator flux. However, the computational burden is a serious obstacle because the required calculations rise exponentially with the extension of the prediction horizon. This is due to a high number of candidate voltage vectors and also predicting the values of several machine variables for these vectors. Different approaches are employed in this work to make the control method computationally tractable. A voltage vector reduction technique is utilised that significantly decreases the total number of enumerated vectors. Moreover, the stator current prediction is eliminated in the proposed method, based on the inherent features of the PMSM. The proposed method is experimentally implemented and its good performance and advantages are verified. [ABSTRACT FROM AUTHOR]

In modern distribution networks, integration of distributed generations (DGs) at consumer premises is common. However, islanding detection in such a grid‐tied distributed generation (GTDG) network is the topmost challenge to ensure power quality and reliable operation. This paper presents a modified passive islanding detection scheme (MPIDS) for the GTDG network, using a One‐D recursive Median filter (ODRMF) algorithm. Firstly, at the point of common coupling (PCC), 3‐phase voltage is acquired. Next, the ODRMF is employed to extract 3rd harmonic and residuals from the acquired voltage signal. Afterward, two novel islanding detection indices developed are: (1) First change detection (FCD), which is calculated from the residuals, and (2) delta selected harmonic distortion (∆SHD), which is computed from 3rd harmonic content of the voltage signal. Finally, variations in the two indices are compared with the threshold to identify islanding. To validate the efficacy of the presented MPIDS, rigorous simulations in MATLAB/ Simulink are conducted on the UL‐1741 and IEEE 13‐bus GTDGs systems under different conditions. The results illustrate that the presented strategy is highly reliable in all assessed conditions and can detect the islanding as well as non‐islanding incidents effectively under balanced and unbalanced load/generation conditions with a very low non‐detection zone. [ABSTRACT FROM AUTHOR]

Given the existence of detent force, the positioning accuracy of permanent magnet linear synchronous motor (PMLSM) with an iron core worsens in its application in the field of the precision drive. To address this problem, a method is proposed to weaken the detent force of PMLSM with a V‐shaped tooth‐slot structure. The models of the detent force, including the cogging force and end force, are established theoretically. The analytical expressions of cogging force and end force are obtained by analysing the ripple rule of the motor. Then, the tooth‐slot surface of the motor with the V‐shaped tooth‐slot structure conducts infinitesimal processing. The relationship between cogging force, end force, and the V‐shaped depth of the V‐shaped tooth‐slot PMLSM is deduced, respectively, using the integration method. Furthermore, Ansoft finite element simulation software Maxwell module is used to compare the conventional PMLSM, V‐shaped magnetic pole PMLSM, and V‐shaped tooth‐slot PMLSM. The comparison reveals that the V‐shaped tooth‐slot structure has the excellent characteristic of increasing the average value of thrust while reducing the ripple of thrust caused by detent force. Finally, prototype fabrication and experiments are conducted to verify the correctness and feasibility of the proposed method. [ABSTRACT FROM AUTHOR]

In three-phase AC motors, three-phase AC voltage system is essential to generate a rotating magnetic field. Three- phase AC motors also require a three-phase inverter for variable speed and torque operation. In general, the number of switching devices used in three-phase inverter is not less than six and decreasing its number is difficult. This paper focuses on an LC ladder circuit consisting of linear inductors and capacitors. This paper presents a new operating method of the AC motor based on a propagating magnetic field. It is successfully excited by connecting one single-phase AC power supply to the end of the LC ladder circuit. The induction motor operated by the presented method produces torque as in general induction motors. [ABSTRACT FROM AUTHOR]

This study presents an Optimized Wind Turbine Emulator (OWTE) based on a DC generator driven by a three-phase Induction Motor (IM). The IM speed is varied using an AC drive that converts fixed RMS voltage and frequency to variable ones due to v/f control. The frequency reference of the control was calculated through optimized equations of a wind turbine model for maximum power and torque. The overall system was simulated on Matlab/Simulink using a wind speed profile scenario. An experimental test bench controlled by a TMS320F28379D card was set up in the laboratory to confirm the effectiveness of the obtained simulation results. [ABSTRACT FROM AUTHOR]

The current standard considers the efficiency of electric motors only in terms of power efficiency and does not pay attention to the so-called economic efficiency - the power factor that affects the loss of electricity in the motor supply network and depends on its energy excellence. This ill-considered approach to establishing the energy efficiency class is a significant shortcoming of the European standard and requires its refinement. The single-phase power supply network in housing and communal services has led to the fact that modern motor compressor units of refrigerators, air conditioners, etc. are equipped with single-phase asynchronous electric motors. An innovative single-phase asynchronous AC motor for motor-compressor units of household appliances is considered in the paper. The stator winding of it is composed of two identical series-connected coils enclosed in half-slots of the stator with a spacious offset of 900 . The phase shift of the currents in the coils is provided by a capacitor connected in parallel to one of the coils. The proposed motor is technological in production, has higher specific power and energy efficiency than existing models and meets the IE-3 class energy efficiency. Equivalent electrical circuit and vector diagram of currents for this motor have been developed and shown. They are intended for its mathematical simulation, calculation of static operating characteristics, analysis of dynamic properties at operation in the electric drive system, and also at the level of design work. [ABSTRACT FROM AUTHOR]

This paper proposes a novel fault detection method for Takagi–Sugeno fuzzy systems via multiple observer design and ellipsoidal analysis. By considering only one fault distribution matrix at a time, the original system is divided into a limited number of fault modes. For each fault mode, an observer with finite‐frequency fault sensitivity performance and full‐frequency unknown inputs robustness performance is designed to generate the residual signal. Based on the designed observer, the ellipsoidal analysis is used to evaluate a residual and to give a fault detection index for each mode. In addition, the fault detection result is provided by combining "or" logical operation of the multiple indices. Numerical simulations and an AC servo motor experimental platform are used to verify the viability and validity of the proposed method. [ABSTRACT FROM AUTHOR]

A sampling error‐based finite‐set predictive current control (FS‐PCC) is proposed in this article for the open‐end winding induction motor (OEWIM) drive. The proposed scheme controls the zero‐sequence current (ZSC) alongside the stator currents. In a model‐free approach, this method predicts the future of ZSC and stator current components by the stator current and voltage sampling errors. In this way, the parameters of the OEWIM are not utilised in the prediction algorithm of the FS‐PCC. So, the proposed method is robust against the variation of the parameter. Moreover, this article presents a simple vector selection technique for the FS‐PCC of the OEWIM. The proposed technique has two cost functions and a simple algebraic equation to put the voltage vectors (VVs) in the prediction algorithm. The first cost function uses VVs that do not have the zero‐sequence voltage component. Then, the algebraic equation determines VVs that must be utilised in the second cost function. Finally, the optimum VV is selected by the second cost function. In the proposed scheme, the prediction algorithm is iterated 14 times instead of 27 iterations of the conventional predictive algorithm. So, besides establishing a novel model‐free prediction algorithm, the proposed method has almost 50% fewer calculations. The validity of the proposed sampling error‐based FS‐PCC and the simplified vector selection technique has been verified through experimental tests. [ABSTRACT FROM AUTHOR]