This document summarizes research on ultrasonic motors. It discusses how ultrasonic motors can be miniaturized for use in medical devices and robots. The researchers designed three types of ultrasonic motors with decreasing size down to 4mm long and 1.6mm diameter. The motors use a hollow cylindrical stator with piezoelectric plates to generate elliptical motion from two orthogonal bending modes. Finite element analysis was used to optimize the design. The motors' performance was characterized using a transient method measuring speed and calculating torque of a loaded rotor.
This document discusses active magnetic bearings (AMBs). It provides background on AMBs, explaining that they support rotating machinery without physical contact using electromagnetic forces controlled by sensors and electronics. The document then describes the basic components and working principles of AMB systems, including electromagnets, position sensors, and control systems that use feedback to maintain the rotor's position. It explains that AMBs offer benefits over traditional bearings like reduced friction, vibration, and maintenance needs. However, it notes that AMB systems are more complex and expensive to implement initially.
Three phase induction motors are complex electro-mechanical devices widely used in most industrial applications. Induction motors are susceptible to many types of fault in industrial application such as rotor bar broken fault, stator inter turn fault, eccentricity fault. Out of these faults eccentricity is very specific in squirrel cage induction motor. If the initial stage of motor failure is not identified will cause the severe damage and production shutdowns. This paper presents the simulations of eccentricity fault detection in three phase squirrel cage induction motor under various load conditions for healthy and faulty conditions. In this paper, dynamic model of induction motor is developed using CAD package called MagNet for static and transient 2D analysis. The various machine parameters like stator current, magnetic flux density, and magnetic torque are calculated and their values are compared under healthy and faulty conditions.
A New Windings Design of 24 Slot Capacitor-Start Capacitor-Run Induction Motor IJECEIAES
The conventional method of a single phase induction motor windings design usually constructed the main and auxiliary windings in both slot. So, there was a complicated winding design if that compare to the three-phase induction motor. Because of that, this study was aimed to design a new windings design of a single phase induction motor that construction like a three-phase induction motor. This study was focused to design a 24 slot capacitor-start capacitor-run induction motor. The windings in the motor are divided in 3 group like a three-phase induction motor. The two windings act as a main windings and the other winding act as auxiliary winding. The current rating of the winding of the proposed single-phase induction motor was 2.74A. The performances of the proposed method were compared with the performances of a three-phase induction motor that had the same current rating. The motor used as a comparator was a three-phase induction of 380/220V, 2.74/4.7A, Y/Δ, cage rotor, 4 poles, 1.5 HP, 1400 RPM, 50Hz. The result of this study showed that the proposed design of single phase induction motor could be operated with better performances than the threephase comparator induction motor‟s.
There are abundant of wave energy converter technologies available to convert wave energy into useable energy. However, most of them are huge and suitable for large application. Thus, this paper aimed to propose portable pico generator designs for small scale application. Investigation on the performance of designs with varying halbach magnet shapes was mainly focused and discussed. Two designs of different magnet shape i.e. triangular and trapezoid were proposed. Open-circuit simulation and optimization results were obtained using Finite Element Method. From the results, it was found out that Trapezoid Magnet Design produced better performance and lower material cost compared to another proposed design, Triangular Magnet as well as conventional Rectangular Magnet shape.
IRJET- Design, Modeling and Simulation of Axial Flux Permanent Magnet Synchro...IRJET Journal
This document summarizes the design, modeling, and simulation of an axial flux permanent magnet synchronous machine for electric vehicles. It begins with an introduction discussing how electrification of vehicles can help reduce pollution from emissions. It then provides an overview of axial flux machines and different topologies. The document focuses on modeling a TORUS-NS (torus non-slotted) type axial flux permanent magnet machine using 2D finite element analysis in Maxwell software. It provides the machine specifications and dimensions used in the simulation. The results obtained from the finite element analysis are then illustrated and discussed.
Stress and Vibration Analysis of Turbine RotorIRJET Journal
This document summarizes the design and analysis of a turbine rotor intended to operate at speeds between 30,000-50,000 RPM. It discusses:
- Designing a blisk rotor using axi-symmetric modeling for stress analysis and optimization.
- Material selection for the rotor, with titanium alloy found to reduce thermal stresses compared to nickel alloy.
- Dynamic analysis showing the first critical speed to be 34,176 RPM, well above the operating speed.
- Stress analysis of the optimized rotor design found highest stresses of 451 MPa to be below the material yield strength.
- The rotor design was concluded to withstand the intended operating stresses and speeds.
Detection of Static Air-Gap Eccentricity in Three Phase induction Motor by Us...IJERA Editor
This paper presents the effect of the static air-gap eccentricity on the performance of a three phase induction motor .The Artificial Neural Network (ANN) approach has been used to detect this fault .This technique depends upon the amplitude of the positive and negative harmonics of the frequency. Two motors of (2.2 Kw) have been used to achieve the actual fault and desirable data at no-load, half-load and full-load conditions. Motor Current Signature analysis (MCSA) based on stator current has been used to detect eccentricity fault. Feed forward neural network and error back propagation training algorithms are used to perform the motor fault detection. The inputs of artificial neural network are the amplitudes of the positive and negative harmonics and the speed, and the output is the type of fault. The training of neural network is achieved by data through the experiments test on healthy and faulty motor and the diagnostic system can discriminate between “healthy” and “faulty” machine.
The document outlines a proposed methodology for analyzing rotor eccentricity in induction motors using simulation. It begins with an introduction on induction motors and rotor eccentricity. A literature review covers techniques used by other researchers to detect eccentricity. The problem statement notes the importance of induction motor condition monitoring. The aims are to simulate normal and eccentric rotor conditions, compare waveforms, and analyze harmonic injection. The proposed methodology includes building a simulation model and collecting eccentricity data. Future work involves thesis writing based on simulation results.
This document discusses active magnetic bearings (AMBs). It provides background on AMBs, explaining that they support rotating machinery without physical contact using electromagnetic forces controlled by sensors and electronics. The document then describes the basic components and working principles of AMB systems, including electromagnets, position sensors, and control systems that use feedback to maintain the rotor's position. It explains that AMBs offer benefits over traditional bearings like reduced friction, vibration, and maintenance needs. However, it notes that AMB systems are more complex and expensive to implement initially.
Three phase induction motors are complex electro-mechanical devices widely used in most industrial applications. Induction motors are susceptible to many types of fault in industrial application such as rotor bar broken fault, stator inter turn fault, eccentricity fault. Out of these faults eccentricity is very specific in squirrel cage induction motor. If the initial stage of motor failure is not identified will cause the severe damage and production shutdowns. This paper presents the simulations of eccentricity fault detection in three phase squirrel cage induction motor under various load conditions for healthy and faulty conditions. In this paper, dynamic model of induction motor is developed using CAD package called MagNet for static and transient 2D analysis. The various machine parameters like stator current, magnetic flux density, and magnetic torque are calculated and their values are compared under healthy and faulty conditions.
A New Windings Design of 24 Slot Capacitor-Start Capacitor-Run Induction Motor IJECEIAES
The conventional method of a single phase induction motor windings design usually constructed the main and auxiliary windings in both slot. So, there was a complicated winding design if that compare to the three-phase induction motor. Because of that, this study was aimed to design a new windings design of a single phase induction motor that construction like a three-phase induction motor. This study was focused to design a 24 slot capacitor-start capacitor-run induction motor. The windings in the motor are divided in 3 group like a three-phase induction motor. The two windings act as a main windings and the other winding act as auxiliary winding. The current rating of the winding of the proposed single-phase induction motor was 2.74A. The performances of the proposed method were compared with the performances of a three-phase induction motor that had the same current rating. The motor used as a comparator was a three-phase induction of 380/220V, 2.74/4.7A, Y/Δ, cage rotor, 4 poles, 1.5 HP, 1400 RPM, 50Hz. The result of this study showed that the proposed design of single phase induction motor could be operated with better performances than the threephase comparator induction motor‟s.
There are abundant of wave energy converter technologies available to convert wave energy into useable energy. However, most of them are huge and suitable for large application. Thus, this paper aimed to propose portable pico generator designs for small scale application. Investigation on the performance of designs with varying halbach magnet shapes was mainly focused and discussed. Two designs of different magnet shape i.e. triangular and trapezoid were proposed. Open-circuit simulation and optimization results were obtained using Finite Element Method. From the results, it was found out that Trapezoid Magnet Design produced better performance and lower material cost compared to another proposed design, Triangular Magnet as well as conventional Rectangular Magnet shape.
IRJET- Design, Modeling and Simulation of Axial Flux Permanent Magnet Synchro...IRJET Journal
This document summarizes the design, modeling, and simulation of an axial flux permanent magnet synchronous machine for electric vehicles. It begins with an introduction discussing how electrification of vehicles can help reduce pollution from emissions. It then provides an overview of axial flux machines and different topologies. The document focuses on modeling a TORUS-NS (torus non-slotted) type axial flux permanent magnet machine using 2D finite element analysis in Maxwell software. It provides the machine specifications and dimensions used in the simulation. The results obtained from the finite element analysis are then illustrated and discussed.
Stress and Vibration Analysis of Turbine RotorIRJET Journal
This document summarizes the design and analysis of a turbine rotor intended to operate at speeds between 30,000-50,000 RPM. It discusses:
- Designing a blisk rotor using axi-symmetric modeling for stress analysis and optimization.
- Material selection for the rotor, with titanium alloy found to reduce thermal stresses compared to nickel alloy.
- Dynamic analysis showing the first critical speed to be 34,176 RPM, well above the operating speed.
- Stress analysis of the optimized rotor design found highest stresses of 451 MPa to be below the material yield strength.
- The rotor design was concluded to withstand the intended operating stresses and speeds.
Detection of Static Air-Gap Eccentricity in Three Phase induction Motor by Us...IJERA Editor
This paper presents the effect of the static air-gap eccentricity on the performance of a three phase induction motor .The Artificial Neural Network (ANN) approach has been used to detect this fault .This technique depends upon the amplitude of the positive and negative harmonics of the frequency. Two motors of (2.2 Kw) have been used to achieve the actual fault and desirable data at no-load, half-load and full-load conditions. Motor Current Signature analysis (MCSA) based on stator current has been used to detect eccentricity fault. Feed forward neural network and error back propagation training algorithms are used to perform the motor fault detection. The inputs of artificial neural network are the amplitudes of the positive and negative harmonics and the speed, and the output is the type of fault. The training of neural network is achieved by data through the experiments test on healthy and faulty motor and the diagnostic system can discriminate between “healthy” and “faulty” machine.
The document outlines a proposed methodology for analyzing rotor eccentricity in induction motors using simulation. It begins with an introduction on induction motors and rotor eccentricity. A literature review covers techniques used by other researchers to detect eccentricity. The problem statement notes the importance of induction motor condition monitoring. The aims are to simulate normal and eccentric rotor conditions, compare waveforms, and analyze harmonic injection. The proposed methodology includes building a simulation model and collecting eccentricity data. Future work involves thesis writing based on simulation results.
1. The document discusses synchronous machines, including their construction, types of prime movers, and excitation systems. It describes salient pole and cylindrical rotors, as well as different winding configurations like distributed, integral slot, and fractional windings.
2. Hydro turbines and diesel engines typically drive synchronous machines with salient pole rotors, while steam turbines drive higher speed machines with cylindrical rotors. Excitation systems can be DC, static using thyristors, or brushless.
3. The document provides an overview of synchronous machines and their components.
Seminar report on axial field electrical machineSaurabh Nandy
This document discusses various types of axial-field electric machines. It begins by introducing axial-field machines and comparing them to conventional radial-field machines. It then describes 10 main configurations of axial-field machines, including the Faraday disk, printed circuit board motors, axial-field induction motors, and torus machines. Applications mentioned include auxiliary power units, wind power generators, electric vehicles, and pumps. The document concludes that axial-field machines can achieve high power-to-weight ratios and may be useful in applications where their characteristics provide advantages over conventional machines.
This document provides an overview of axial-field electrical machines. It discusses various types of axial-field machines including single stator/rotor designs, central stator designs, and multi-disc designs. It also compares axial-field machines to conventional radial-field machines and summarizes some of their advantages such as higher power-to-weight ratios and ability for internal cooling via the rotating discs. Several specific axial-field machine designs are described in detail such as Faraday disks, printed circuit motors, and Torus machines. A wide range of applications are listed that could benefit from the special features of axial-field machines.
Speed Control System of Induction Motor by using Vector Control Methodijtsrd
In the Vector Control method of induction motors, one of the advantages of the separately excited DC motor of being able to decouple the flux control and the torque is thereby opened up. The field orientation control of induction motor allows decoupling the control of magnetic flux and the control of the torque produced by the stator current. To drive three phase squirrel cage induction motor with a constant speed, vector control technique is used. In this paper, the development of speed control system for three phase squirrel cage induction motor using a vector control method is presented and simulation for proposed system is done with the help of MATLAB SIMULINK. Soe Sandar Aung | Thet Naing Htun "Speed Control System of Induction Motor by using Vector Control Method" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd27914.pdfPaper URL: https://www.ijtsrd.com/engineering/electrical-engineering/27914/speed-control-system-of-induction-motor-by-using-vector-control-method/soe-sandar-aung
Detection of Broken Bars in Three Phase Squirrel Cage Induction Motor using F...Dr.NAGARAJAN. S
Finite element method is more precise than the winding function approach, as it is based on the actual geometry of the machine and the machine model can easily be modified in order to study the effect of faults on the machine’s performance. Accurate models of the machine under healthy and faulty conditions are developed. This paper presents simulations of broken bars detection in a three phase squirrel cage induction motor under no load, half load and full load conditions for two and eight broken bars. The analysis is done using MagNet.
Design and fabrication of rotor lateral shifting in the axial-flux permanent-...IJECEIAES
The development of axial-flux permanent-magnet (AFPM) machines has become a mature technology. The single-stator double-rotor (SSDR) AFPM structure has advantages on the compactness and the low up to medium power applications so the microscale size and low-cost applications are reachable to be designed. The research main objectives are designing and manufacturing the lateral shifting from the north poles of the first rotor face the north poles of the second rotor (NN) to the north poles of the first rotor face the south poles of the second rotor (NS) categories as well as finding the best performance of the proposed method and implementing in a low cost and micro-scale AFPMG. The novel lateral shifting on the one of the rotors shows performance at 19.2 0 has the highest efficiency at 88.39% during lateral shifting from N–N (0 0 ) to N–S (36 0 ) on rotor 2.
The trend in the motor applications is to reduce weight and volume by increasing the efficiency. Because of the advantage of high efficiency and high density, interest in brushless DC motors and drives is increasing. Unlike DC motors, the brushless DC (BLDC) motors require inverter circuit and position detector. In this paper, we deal with the optimization of the BLDC motor, the inverter, and the position detector. The inverter is optimized to be mounted on the BLDC motor. This paper deals primarily with the design and implementation aspects of the BLDC motor and the integrated drive circuit. Experimental results for the prototype of the BLDC motor with integrated dirve circuit in the laboratory are presented to validate the feasibility.
Critical Condition of Sensorless Induction Generator using Flux Weakening in ...IAES-IJPEDS
This paper was intended to examine thoroughly a critical condition of the
sensorless induction generator using flux weakening in wind turbine
application. The critical condition would happen when the rotor speed
reached the critical rotor speed reference. The critical rotor speed reference
was the highest of the rotor speed reference that still caused the stable
response. It was obtained by increasing the rotor speed reference until the
system response became unstable. In the low speed range of wind showed
that there was no unstable condition whatever a rotor speed reference was
set. On the other hand, there was a critical rotor speed reference in the
medium and high speed range of wind. The unstable condition was caused by
the induction generator that received a power higher than its capacity, so its
rotor speed couldn't be maintained at reference value. The first solution was
suggested that the stable condition would be made by setting the rotor speed
reference at the minimum critical reference. The second solution was
suggested that the controlling rotor speed in triangle area between the critical
condition and the operation that used the minimum critical reference for the
rotor speed reference. In the triangle area, the rotor speed was controlled by
setting the tip speed ratio.
Critical Condition of Sensorless Induction Generator using Flux Weakening in ...IAES-IJPEDS
This paper was intended to examine thoroughly a critical condition of the
sensorless induction generator using flux weakening in wind turbine
application. The critical condition would happen when the rotor speed
reached the critical rotor speed reference. The critical rotor speed reference
was the highest of the rotor speed reference that still caused the stable
response. It was obtained by increasing the rotor speed reference until the
system response became unstable. In the low speed range of wind showed
that there was no unstable condition whatever a rotor speed reference was
set. On the other hand, there was a critical rotor speed reference in the
medium and high speed range of wind. The unstable condition was caused by
the induction generator that received a power higher than its capacity, so its
rotor speed couldn't be maintained at reference value. The first solution was
suggested that the stable condition would be made by setting the rotor speed
reference at the minimum critical reference. The second solution was
suggested that the controlling rotor speed in triangle area between the critical
condition and the operation that used the minimum critical reference for the
rotor speed reference. In the triangle area, the rotor speed was controlled by
setting the tip speed ratio.
Induction motor is a veritable machine in the industries today, since is the most widely used electric motor in the
industry. It offers a reasonable performance, manageable torque/speed characteristics and a better efficiency. The aim of this
paper is to examine a comparative analysis of a three phase induction motor for performance evaluation. The computer simulation
and experimental methods were used to carry out the investigations, validation and evaluation of the behavioural characteristics of
the machine. The simulation and experimental results obtained were compared to validate the results obtained from the
experimental method. It was shown that the results from the simulation and experimental methods were in agreement with the
theoretical values of the three phase induction motor. Thus, the results indicated that the relative errors were negligible and the
proposed simulation models accurately predict the equivalent circuit parameters of the induction motor.
This document presents a mathematical model of ball bearing anomalies in induction machines. It begins with background on ball bearing failures accounting for around 50% of induction machine breakdowns. It then discusses modeling the kinematic frequencies of ball bearings and developing models to represent anomalies on the outer ring and inner ring. The outer ring anomaly is modeled as a series of radial pulses with a frequency equal to the ball rotation frequency around the outer ring. The inner ring anomaly is modeled in a reference frame rotating with the inner ring speed. The modeling aims to analyze the effects of anomalies on electrical and mechanical quantities of the machine and its stability during operation.
Speed torque characteristics of brushless dc motor in either direction on loa...Alexander Decker
1. The document discusses the speed-torque characteristics of a brushless DC motor when operating in both forward and reverse directions under load using an ARM controller.
2. A three-phase bridge inverter with MOSFET switches is used to convert DC power to the three-phase AC needed to drive the brushless DC motor. Hall sensors provide position feedback to the ARM controller to control the switching of the inverter.
3. Experiments were conducted where a dynamometer was used to apply variable loads to the motor. Speed-torque characteristics were measured for operation in both directions.
Abstract This Paper Proposes is to design a magnetic actuator to deal with the modeling and optimization of Solenoid actuator (Magnetic Actuator). The design is very important step for the study proportional solenoid valve. The magnetic actuator includes design optimization, micro analysis and calculations and experimental characterization one of the magnetic actuator. All these magnetic actuators work in sub- micron level movement used in micro system and valve applications. Proportional solenoid valve designed in find out the magnetic force (N), magnetic field intensity (A/m), magnetic flux density (Tesla or wb/m2). To enhance the magnetic force and reduction of size by magnetic field in air gap of solenoid valve. Permanent magnetic bias magnetic actuator study for bidirectional application using different permanent magnet material and optimization of size of armature. Key Words: Electromagnet, Solenoid actuator, Modeling, Design Rules,
This document discusses analyzing faults in induction motors using finite element analysis with Magnet software. It first describes modeling a healthy 1HP three-phase induction motor in Magnet, including dimensions of the stator, rotor, shaft, bearings, and end rings. Broken rotor bars are then introduced as a fault to study the variation in starting torque. Magnetic field analysis is performed on the healthy and faulty motor models.
This document discusses modeling and field oriented control (FOC) of a permanent magnet synchronous motor (PMSM) using MATLAB/Simulink. It first introduces PMSM drives and their components. It then presents the mathematical modeling of a PMSM in the d-q reference frame. This includes developing the voltage and flux linkage equations. It also discusses Parks transformation and the equivalent circuit model. Next, it covers PMSM control strategies like FOC which allows controlling the motor like a DC motor. It provides the details of FOC implementation including constant torque control. Finally, it discusses establishing the FOC simulation model in MATLAB/Simulink to simulate the control system.
This document provides an overview of ultrasonic motors. It discusses that ultrasonic motors use piezoelectric elements to generate ultrasonic vibrations that produce rotational or linear motion. The vibrations are amplified through resonance. Advantages over electromagnetic motors include high torque at low speeds, compact size, and insensitivity to magnetic fields. The document then describes various prototypes of linear and rotary ultrasonic motors and their design and modeling. It provides details on the operating principles and applications of ultrasonic motors.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
This document discusses basic principles and functions of electrical machines. It provides classifications of electric machines according to power supply and NEMA standards. The key components and operating principles of DC and AC machines are described. Methods for determining machine parameters like resistance and reactance are outlined. The document also covers protection, maintenance, and applications of electric machines.
This document provides a literature survey on fault detection techniques for inverter-fed three-phase squirrel cage induction motors. It summarizes over 30 previous research papers on topics like broken rotor bars, stator faults, eccentricity, bearing faults, and fault-tolerant inverter drives. The survey covers various modeling, simulation, and experimental approaches to motor fault detection using techniques like motor current signature analysis, finite element analysis, and signal processing methods.
This paper discusses about winding arrangement of fractional slot of a new type hollow rotor Brushless Direct Current (BLDC) motor. Hollow rotor has higher performance compared to other BLDC motor because it minimizes the unused flux below permanent magnet and maximize torque produce by the motor. It’s also known that 8 pole motor is favorite used in industrial because it has an optimum space of permanent magnet for a smaller motor size. The number of pole will affect the maximum speed of the rotor. Thus, the objective of this research is to investigate the best winding arrangement for 8 pole of hollow rotor that could produce the highest electromagnetic performance. At starts, four combinations of slot number and coil sizes had been selected. Structural comparison in term of coil vector and winding arrangement is studied. Finite Element Method (FEM) had been used to simulate the parameters such as backemf and torque waveforms. It was convinced that 9 slot 8 pole with 0.6 size of coil produces the best performance. The confirmed model had been fabricated and measured. Both results from FEM and measurement are compared in term of backemf and torque where percentage differences are 7.4 % and 8 %, respectively. As conclusion, this research shows the fundamental of winding arrangement of fractional slot of motor especially 8 pole motor.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
1. The document discusses synchronous machines, including their construction, types of prime movers, and excitation systems. It describes salient pole and cylindrical rotors, as well as different winding configurations like distributed, integral slot, and fractional windings.
2. Hydro turbines and diesel engines typically drive synchronous machines with salient pole rotors, while steam turbines drive higher speed machines with cylindrical rotors. Excitation systems can be DC, static using thyristors, or brushless.
3. The document provides an overview of synchronous machines and their components.
Seminar report on axial field electrical machineSaurabh Nandy
This document discusses various types of axial-field electric machines. It begins by introducing axial-field machines and comparing them to conventional radial-field machines. It then describes 10 main configurations of axial-field machines, including the Faraday disk, printed circuit board motors, axial-field induction motors, and torus machines. Applications mentioned include auxiliary power units, wind power generators, electric vehicles, and pumps. The document concludes that axial-field machines can achieve high power-to-weight ratios and may be useful in applications where their characteristics provide advantages over conventional machines.
This document provides an overview of axial-field electrical machines. It discusses various types of axial-field machines including single stator/rotor designs, central stator designs, and multi-disc designs. It also compares axial-field machines to conventional radial-field machines and summarizes some of their advantages such as higher power-to-weight ratios and ability for internal cooling via the rotating discs. Several specific axial-field machine designs are described in detail such as Faraday disks, printed circuit motors, and Torus machines. A wide range of applications are listed that could benefit from the special features of axial-field machines.
Speed Control System of Induction Motor by using Vector Control Methodijtsrd
In the Vector Control method of induction motors, one of the advantages of the separately excited DC motor of being able to decouple the flux control and the torque is thereby opened up. The field orientation control of induction motor allows decoupling the control of magnetic flux and the control of the torque produced by the stator current. To drive three phase squirrel cage induction motor with a constant speed, vector control technique is used. In this paper, the development of speed control system for three phase squirrel cage induction motor using a vector control method is presented and simulation for proposed system is done with the help of MATLAB SIMULINK. Soe Sandar Aung | Thet Naing Htun "Speed Control System of Induction Motor by using Vector Control Method" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd27914.pdfPaper URL: https://www.ijtsrd.com/engineering/electrical-engineering/27914/speed-control-system-of-induction-motor-by-using-vector-control-method/soe-sandar-aung
Detection of Broken Bars in Three Phase Squirrel Cage Induction Motor using F...Dr.NAGARAJAN. S
Finite element method is more precise than the winding function approach, as it is based on the actual geometry of the machine and the machine model can easily be modified in order to study the effect of faults on the machine’s performance. Accurate models of the machine under healthy and faulty conditions are developed. This paper presents simulations of broken bars detection in a three phase squirrel cage induction motor under no load, half load and full load conditions for two and eight broken bars. The analysis is done using MagNet.
Design and fabrication of rotor lateral shifting in the axial-flux permanent-...IJECEIAES
The development of axial-flux permanent-magnet (AFPM) machines has become a mature technology. The single-stator double-rotor (SSDR) AFPM structure has advantages on the compactness and the low up to medium power applications so the microscale size and low-cost applications are reachable to be designed. The research main objectives are designing and manufacturing the lateral shifting from the north poles of the first rotor face the north poles of the second rotor (NN) to the north poles of the first rotor face the south poles of the second rotor (NS) categories as well as finding the best performance of the proposed method and implementing in a low cost and micro-scale AFPMG. The novel lateral shifting on the one of the rotors shows performance at 19.2 0 has the highest efficiency at 88.39% during lateral shifting from N–N (0 0 ) to N–S (36 0 ) on rotor 2.
The trend in the motor applications is to reduce weight and volume by increasing the efficiency. Because of the advantage of high efficiency and high density, interest in brushless DC motors and drives is increasing. Unlike DC motors, the brushless DC (BLDC) motors require inverter circuit and position detector. In this paper, we deal with the optimization of the BLDC motor, the inverter, and the position detector. The inverter is optimized to be mounted on the BLDC motor. This paper deals primarily with the design and implementation aspects of the BLDC motor and the integrated drive circuit. Experimental results for the prototype of the BLDC motor with integrated dirve circuit in the laboratory are presented to validate the feasibility.
Critical Condition of Sensorless Induction Generator using Flux Weakening in ...IAES-IJPEDS
This paper was intended to examine thoroughly a critical condition of the
sensorless induction generator using flux weakening in wind turbine
application. The critical condition would happen when the rotor speed
reached the critical rotor speed reference. The critical rotor speed reference
was the highest of the rotor speed reference that still caused the stable
response. It was obtained by increasing the rotor speed reference until the
system response became unstable. In the low speed range of wind showed
that there was no unstable condition whatever a rotor speed reference was
set. On the other hand, there was a critical rotor speed reference in the
medium and high speed range of wind. The unstable condition was caused by
the induction generator that received a power higher than its capacity, so its
rotor speed couldn't be maintained at reference value. The first solution was
suggested that the stable condition would be made by setting the rotor speed
reference at the minimum critical reference. The second solution was
suggested that the controlling rotor speed in triangle area between the critical
condition and the operation that used the minimum critical reference for the
rotor speed reference. In the triangle area, the rotor speed was controlled by
setting the tip speed ratio.
Critical Condition of Sensorless Induction Generator using Flux Weakening in ...IAES-IJPEDS
This paper was intended to examine thoroughly a critical condition of the
sensorless induction generator using flux weakening in wind turbine
application. The critical condition would happen when the rotor speed
reached the critical rotor speed reference. The critical rotor speed reference
was the highest of the rotor speed reference that still caused the stable
response. It was obtained by increasing the rotor speed reference until the
system response became unstable. In the low speed range of wind showed
that there was no unstable condition whatever a rotor speed reference was
set. On the other hand, there was a critical rotor speed reference in the
medium and high speed range of wind. The unstable condition was caused by
the induction generator that received a power higher than its capacity, so its
rotor speed couldn't be maintained at reference value. The first solution was
suggested that the stable condition would be made by setting the rotor speed
reference at the minimum critical reference. The second solution was
suggested that the controlling rotor speed in triangle area between the critical
condition and the operation that used the minimum critical reference for the
rotor speed reference. In the triangle area, the rotor speed was controlled by
setting the tip speed ratio.
Induction motor is a veritable machine in the industries today, since is the most widely used electric motor in the
industry. It offers a reasonable performance, manageable torque/speed characteristics and a better efficiency. The aim of this
paper is to examine a comparative analysis of a three phase induction motor for performance evaluation. The computer simulation
and experimental methods were used to carry out the investigations, validation and evaluation of the behavioural characteristics of
the machine. The simulation and experimental results obtained were compared to validate the results obtained from the
experimental method. It was shown that the results from the simulation and experimental methods were in agreement with the
theoretical values of the three phase induction motor. Thus, the results indicated that the relative errors were negligible and the
proposed simulation models accurately predict the equivalent circuit parameters of the induction motor.
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Ultrasonic Motors
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2. ULTRASONIC MOTORS
Serra Cagatay‡
, Kenji Uchino‡
and Burhanettin Koc†
‡ International Center for Actuators and Transducers, Materials Research
Institute, The Pennsylvania State University, University Park, PA, 16802.
†Atilim University, Mechatronics Engineering, Ankara, Turkey.
1. Introduction
Ultrasonic motors, which have superior characteristics like high torque at low
speed, absence of magnetic interference, and compactness in size, are good candidates for
medical applications, automation, robotics, aerospace engineering and various other
fields. Many different types of ultrasonic motors have been proposed up to date [1]-[5].
The stator of an ultrasonic motor that is excited by piezoelectric elements in
ultrasonic frequency range develops different kinds of vibrations depending on its
structure. From the way of creating an elliptical motion on the stator, ultrasonic motors
were classified into two major groups, such as standing wave and traveling wave types.
Further classifications include mode-conversion, multi-mode [6,7,8] and mode-rotation
types of motors [9] that are suitable for miniaturization and can be manufactured less
costly.
Ultrasonic motors are of great interest due to the flexibility of miniaturization in
comparison with conventional electromagnetic motors whose efficiency decreases
significantly. Especially in information systems [4] and medical industry [10], compact
size of these motors makes them find wider applications.
2. Objective
The miniaturization of a mechatronic device depends on the size of the motor
equipped in the device to run it. Miniaturization of conventional electromagnetic motors
to several millimeters with high efficiency is difficult since a gear mechanism is required
to obtain a high torque from the electromagnetic motor. This mechanism adds additional
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4. mass, volume and complexity and also increases the number of components of the
system, which decreases the motor system reliability. On the other hand, piezoelectric
ultrasonic motors are suitable for miniaturization in terms of their compactness and low
power consumption.
Our main objective is to design, fabricate and characterize piezoelectric ultrasonic
motors for micromechatronic devices. The approach in designing these piezoelectric
motors were as follows:
i. To simplify the structure including the poling configuration of
piezoelectric element used in stator.
i. To reduce the number of components in order to decrease the cost and
enhance the driving reliability.
The designed motors are a multi-mode-single-vibrator excitation type, which uses
two orthogonal bending modes of a hollow cylinder. Since the structure and poling
configuration of the active piezoelectric elements used in the stator are simple, these
motor structures are very suitable for miniaturization. Moreover, a single driving source
can excite two bending modes at the same time, thus generate a wobble motion.
There are 3 types of ultrasonic motors. The piezoelectric stator structure is the
same for all of these motors. However, the dimensions of the motor are reduced by
almost 50 percent. Starting with a 10 mm long stator, we reached down to 4 mm in the
last model. The initial diameter was 2.4 mm and it went down to 1.6 mm. In the final
design, the rotor part of the motor had been changed and this resulted in a reduction in the
number of components. In terms of driving circuit, a single driving source was enough to
run the motor and a conventional switching power supply type resonant L-C circuit was
used.
3. Structures and Operating Principles of Motors
A square beam has two orthogonal bending modes whose resonance frequencies
are equal to each other. The first bending mode frequencies in any direction for circular
cylinders are also equal to each other. The stator of the motor combines the circular and
square cross-sections.
5. The outside surface of a hollow metal cylinder was flattened on two sides at 90-
degrees to each other and two uniformly electroded rectangular piezoelectric plates were
bonded onto these two flattened surfaces (Fig.1 (a)). The basic configuration of the motor
is shown in Fig.1 (b). Since the stator is symmetric with respect to the x'-axis, the area
moment of inertia about the principal axis is on the x'-axis. The area moment of inertia
about the other principal axis is on the y'-axis. This causes the stator to have two
degenerated orthogonal bending modes, whose resonance frequencies are close to each
other. The split of the bending mode frequencies is due to the partially square/partially
circular outside surface of the hollow cylinder. Driving one piezoelectric plate (while
short circuiting the other to ground) at a frequency between the two orthogonal bending
mode frequencies excites both modes, thus, causing the cylinder to wobble. When the
other piezoelectric plate is driven at the same frequency, the direction of wobble motion
is reversed.
(b)
(a)
Fig.1. (a) Structure of the stator (b) Assembly of the motor.
4. Finite Element Analysis
The behavior of the free stator was simulated using ATILA finite element
software to verify the conceptual operation principle. Tailoring dimensions of the metal
and piezoelectric ceramics equated the two orthogonal bending mode frequencies of the
6. stator. The piezoelectric plates on the surface of the cylinder were placed in such a way
that one piezoelectric plate can excite the two orthogonal bending modes of the stator.
Fig.2 (a) shows the two orthogonal bending mode shapes when only the plate on
the x-axis (plate X) was excited, while the electrode of the plate Y was short-circuited.
Wobble motion was generated on the cylinder when only one piezoelectric plate is
excited at a frequency between the two orthogonal bending modes frequencies (Fig.2
(b)). When the other piezoelectric plate was excited at the same frequency, the direction
of wobble motion was reversed.
Plate X
Plate Y
(a) (b)
Fig.2. (a) Two orthogonal mode shapes when plate in x-axis was excited, (b)
Wobble motion in clockwise direction can be generated on the cylinder when plate in x-
axis was excited in between the two orthogonal bending resonance frequencies.
5. Set-up for the Characterization of the Motors
The performance of the motors was measured using a transient characterization
method, which was initially proposed by Nakamura [11]. The principle of this method is
mounting a load (usually a disk whose moment of inertia is known) onto the motor,
7. running the motor, and, finally, analyzing the transient speed obtained as a function of
time. More explicitly, the angular acceleration of the motor is calculated from the speed
measurement by Newton's second law.
The transient torque is then calculated by multiplying the angular acceleration
with the moment of inertia of the load. Using this method, the starting transient response
of the motor gives the speed-torque relation. A load is mounted onto the stator and the
motor is then driven with an AC voltage. The position of the rotating disk is detected
through an optical encoder. The transient position data were then converted into voltage
signal using a frequency-to-voltage converter.
Since the output voltage of the converter is proportional to the input frequency,
the speed of the motor was obtained. The angular acceleration of the motor was estimated
using the derivative of the angular speed. Finally, the transient torque was calculated by
multiplying the angular acceleration with the moment of inertia of the rotating disk.
6. Structural Properties and Characteristics of the Motors
So far, 3 motors were fabricated. Table 1 summarizes the structural properties of
these motors. As can be seen from Table 1, there is a gradual reduction in the dimensions
and a reduction in the total length of the whole motor structure.
Table 1. Structural Properties of the Motors
Dimensions 1st
Design 2nd
Design 3rd
Design
Outer Diameter (mm) 2.4 1.6 1.6
Inner Diameter (mm) 1.6 0.8 0.8
Thickness of Ceramic Plates 0.5 0.3 0.3
Length of Stator 10 6 4
1st
Design
The outside surface of the metal cylinder was ground on two sides at 90-degrees
to each other to obtain two orthogonal flat surfaces. The PZT plates, which were
8. electroded uniformly and poled in the thickness direction, were bonded onto the flat
orthogonal surfaces of the cylinder using an epoxy. The rotor was a cylindrical rod and it
was pressed by a spring using a pair of stainless steel ferrules. A picture of this motor can
be seen in Fig.3.
s a first step to clarify the behavior of the stator, the admittance spectra of the
free sta
Fig 3. 1st
design
A
tor were measured (Fig.4) when plate X or Y was excited. When plate X was
excited while short-circuiting the electrode of plate Y to the ground, the stator had two
degenerated bending mode resonance frequencies around 71.8 and 74.0 kHz. When plate
Y was excited, the stator showed a similar behavior.
Fig.4. Magnitude of admittance spectrum
of the free stator when plate X or Y was
excited
9. The wobble motion in the XY-plane was also verified by measuring the
magnitude of the vibration velocity in x and y directions at the same time. A function
generator (HP33120A) and a power amplifier (NF4010) were used to excite the stator. By
exciting either plate X or plate Y, the elliptical displacements in x and y directions were
measured with two laser fiber optic interferometers.
First, plate X was excited at frequencies of 70.7, 71.6, 72.2, 73, 74, 75, 76 kHz,
with an input voltage of 112.0 V p-to-p. The results are plotted in Fig.5 (a). The
measurements were repeated by exciting only plate Y and the results are shown in Fig.5
(b).
(a)
(b)
Fig.5. Elliptical displacements at frequencies 70.7, 71.6, 72.2, 73, 74, 75 and 76 kHz
(a) when plate X was excited and, (b) when plate Y was excited.
10. The interesting points here are: i) the direction of wobble motion when only plate
X was excited was clockwise, and counterclockwise when only plate Y was excited, ii)
the wobble motion, when only plate X was excited, was almost identical to the wobble
motion when only plate Y was excited at the same frequency. In conclusion, the designed
motor can be driven with a single AC source and exciting either plate X or Y, the
direction of the rotation can be reversed.
In terms of load characteristics of the motor, transient speed, torque and efficiency
were measured and calculated. A load, a metal disk (60 g) with a diameter of 34 mm and
moment of inertia (8.6 kg⋅mm2
) was mounted onto the stator. As shown in Fig.6, the
steady state speed reached 86 rad/sec in 7 sec. A starting torque of 1.8 mNm at 120 Volt
is similar to other bulk piezoelectric cylindrical type micro motors in literature and
almost one order of magnitude higher than that of a thin film motor with a similar size
[12-14].
Fig.6. Transient response of the motor
The product of output torque with output speed gives the output power. A
maximum power of 60 mW was obtained at a speed of 60 rad/sec and a torque of 1
mNm. The maximum efficiency of 25 % (Fig.7) at 120 V is similar to other bulk
cylindrical type micro piezoelectric motor [14].
11. Fig. 7. Load Characteristics of the
Motor
2nd
Design
The principle is the same as the previous motor. The important improvement is in
the reduction of the dimensions of the stator almost by half of the previous one.
Fabricated motor can be seen in Fig.8.
Fig.8. 2nd
design
Simulation of the stator was performed by ATILA finite element software to
determine the bending modes of the structure. The two orthogonal bending frequencies
were observed at 128 kHz and 132 kHz.
12. Experimental set-up for measuring load characteristics is the same as the previous
one and the results are as follows. The steady state speed was obtained as 67 rad/sec in 7
sec. A maximum torque of 0.87 mNm was obtained. The motor reached a maximum
power of 45 mW at a speed of 45 rad/sec. The maximum efficiency was 12 %. The power
of the motor is dependent on the size of the piezoelectric ceramics used. As the thickness
and the length of the components were reduced, a lower output power was obtained.
3rd
Design
This motor is the smallest of all three designs. The diameters of the stator part are
the same as that of 2nd
motor. However, the length is reduced to 4 mm and also the rotor
part has changed completely. Instead of a solid metal rod, a spring was used as a shaft.
This spring acts as a rotor and as a pre-stress element, as well. Apparently, the number of
components was minimized. A picture of this motor can be seen in Fig.9.
Fig.9. 3rd
design
The resonance frequency of the stator is in the range of 230-245 kHz. As the
length of the ceramic plates reduced down to 4 mm, the working frequency increased
relatively. Maximum torque and power are 0.3 mNm and 25 mW, respectively. Table 2
summarizes the important characteristics of all motors.
13. Table 2. Characteristics of the motors
1st
(10 mm) 2nd
(6 mm) 3rd
(4 mm)
Frequency Range 65-75 kHz 125-140 kHz 230-245 kHz
Steady State Speed 86 rad/sec 67 rad/sec 50 rad/sec
Torque 1 mNm 0.87 mNm 0.30 mNm
Power 60 mW 45 mW 25 mW
To summarize, Table 3 compares the structural differences of all fabricated
motors. The objectives to miniaturize and to simplify the structure of the proposed motor
design were achieved successfully.
Table 3. Comparison of the designs
1st
2nd
3rd
Length of the Stator 10 6 4
Total Length of the
Motor
~ 15 ~11 ~5
Number of
Components Used
2 piezoelectric plates
+
spring+ferrule+rotor
5
2 piezoelectric plates
+
spring+ferrule+rotor
5
2 piezoelectric plates
+
ferrule+ spring (as a rotor)
4
7. Driving Circuit
Current trend for driving ultrasonic motors consists of using switching amplifiers.
The reason is that they considerably reduce the heat generated by the piezoelectric
element.
For the 3rd
design, a switching power amplifier type driving circuit was used.
Major feature of this kind of circuit is that it acts as a voltage regulator. As load
requirements change, voltage variations also occur. This kind of voltage regulator circuit
is capable of establishing and maintaining a nearly constant dc output voltage.
A schematic diagram of the circuit is shown in Fig. 10.
14. Fig. 10. Schematic of the driving circuit
8. Conclusion
The design, fabrication and characterization of a piezoelectric ultrasonic
micromotor have been investigated.
The piezoelectric motor makes use of two orthogonal bending modes of a hollow
cylinder. The vibrating element, stator, of the motor consists of a brass tube and two
piezoelectric plates bonded to two flattened surfaces of the tube.
Three different motors were fabricated. In the first two designs, a solid stainless
steel was used as a shaft, a spring as a pre-stress and a ferrule to hold the rod and the
spring. Major improvement of the 2nd
motor with respect to the 1st
one was the reduction
in the dimensions of the stator. 3rd
motor was the smallest in length of all and the shaft
was replaced with a spring. Consequently, miniaturization and simplification of the
proposed design were achieved.
All three motors were characterized individually. Admittance spectra of the free
stators, torque, power and efficiency values of each motor were presented.
Driving of the motor was enabled by a switching power supply. It is conventional
and cheap.
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