Phase Asynchronous Motor Research Articles

Real-time Implementation of a Single Phase Asynchronous Motor Drive, Feeding within an Open Energy Source

A modified nanogrid (MnG) is a very small scalable grid with a low power single-input multi-output (SIMO) inverter. This inverter simultaneously produces both AC and DC currents, such as the switched boost inverter (SBI) and the z-source inverter. These inverters are suitable for low-power loads such as home appliances that use fractional horse-power motors as single-phase asynchronous drives. Thus, this article proposes a single-phase induction motor powered from a modified nanogrid that involves multiple types of inverters such as a SBI and a ZS inverter. The modified nanogrid is mainly dependent on photovoltaic (PV) as a renewable resource. Thus, this manuscript involves a full design for this proposed grid with its maximum power point tracking (MPPT) and the mathematical models for motor drive with both a SBI and a ZSI. Time-varying speed trajectories are proposed to test the robustness of the proposed drives relative to the fluctuation of PV-parameters like its irradiance. Test results are obtained using the Matlab/ Simulink software package and a comparison with the traditional sinusoidal pulse width modulation (SPWM) inverter as a single-input single-output inverter (SISOI). The results indicate that the proposed single-input multi-output inverters are suitable for driving these motors through start-up and operation, although the DC-link voltage is minimized. Furthermore, the proposed system is experimentally implemented with OPAL RT-4510v real-time hardware in the loop (HIL), rapid control prototyping, and OP-8660 HIL controller and data acquisition platform.

Advanced Grid Connected Solar Variable Speed Drive for Three Phase Asynchronous Motors. (Dept. E)

Advanced Grid Connected Solar Variable Speed Drive for Three Phase Asynchronous Motors. (Dept. E)

Speed sensorless control of seven phase asynchronous motor drive system using extended Kalman filter

ABSTRACT In recent decades, multiphase motors are used in numerous applications instead of three-phase A synchronous motors, due to many advantages they offer. Eliminating mechanical position or speed sensor attractions for A synchronous motor (IM) adjustable speed drives. This results in lower maintenance, cost reduction and improved drive system reliability. Based on measured stator voltages and currents at motor terminals, the rotor mechanical speed is estimated to eliminate the speed sensor. This paper presents a seven-phase asynchronous motor Extended Kalman Filter System speed observer to improve the drive reliability of a seven-phase IM drive sensorless Indirect Rotor Field Oriented Control (IRFOC). The proposed scheme is simulation using the Matlab/Simulink package and evaluated experimentally. The proposed drive system provides good performance under various operating conditions.

Fault Detection based on MCSA for a 400Hz Asynchronous Motor for Airborne Applications

Future health monitoring concepts in different fields of engineering require reliable fault detection to avoid unscheduled machine downtime. Diagnosis of electrical induction machines for industrial applications is widely discussed in literature. In aviation industry, this topic is still only rarely discussed. A common approach to health monitoring for electrical induction machines is to use Motor Current Signature Analysis (MCSA) based on a Fast Fourier Transform (FFT). Research results on this topic are available for comparatively large motors, where the power supply is typically based on 50Hz alternating current, which is the general power supply frequency for industrial applications.
 In this paper, transferability to airborne applications, where the power supply is 400Hz, is assessed. Three phase asynchronous motors are used to analyse detectability of different motor faults. The possibility to transfer fault detection results from 50Hz to 400Hz induction machines is the main question answered in this research work. 400Hz power supply frequency requires adjusted motor design, causing increased motor speed compared to 50Hz supply frequency. The motor used for experiments in this work is a 800W motor with 200V phase to phase power supply, powering an avionic fan. The fault cases to be examined are a bearing fault, a rotor unbalance, a stator winding fault, a broken rotor bar and a static air gap eccentricity. These are the most common faults in electrical induction machines which can cause machine downtime. The focus of the research work is the feasibility of the application of MCSA for small scale, high speed motor design, using the Fourier spectra of the current signal.
 Detectability is given for all but the bearing fault, although rotor unbalance can only be detected in case of severe damage level. Results obtained in the experiments are interpreted withrespect to the motor design. Physical interpretation are given in case the results differ from those found in literature for 50Hz electrical machines.

Direct Torque Control for Induction Motor Drive with Reduced Torque and Flux Ripples

The most universally used electric motor is an induction motor fed with three phase supply and eighty percent of mechanical power utilized by industries is given by three phase asynchronous ac motor. Direct torque control method is one such technique for controlling flux and torque of an asynchronous motor fed with PWM VSI. Without any complex control algorithms, it provides easy commands for the control of induction motor flux as well as torque. We are demonstrating the principle of DTC of an asynchromous motor using three level hysteresis controller in this paper. Philosophy of DTC with aforementioned control method has been simulated using MATLAB/Simulink.

Double PWM coordinated control based on model predictive algorithm and power compensation

With analysis on double PWM structure though system's energy flow theory, active power and reactive power of rectifier are controlled by model predictive algorithm. System adopts the method of combine dynamic power's compensation with static power's compensation for system power in order to reduce system power error. A new power compensation algorithm is proposed to designs a new controller to replace PI controller of system's voltage loop, which can restrain fluctuation of DC bus voltage when load power suddenly varies and reduces DC-link's capacity of capacitance. As for inverter side, the system uses the method of rotor flux linkage oriented to control three phase asynchronous motor. Results of simulation can show that, system can realise the smallest tracking error of active power and reactive power by model predictive control, and restrain fluctuation of DC bus when load power suddenly changes. As the same time, the gird current's waveform is well.

Methods of Vector Control for Induction Motors

This paper presents the electrical and mathematical models of the three phase asynchronous motors along with the introduction of the field-oriented control model as well as the vector transformations needed for the introduction of the above mentioned terms. The objective of the present paper is to introduce the space vectors and how to build the field-oriented control for a given induction motor drive as well as the transformations and the modell of field oriented control.

A Low cost modelling of the variable frequency drive optimum in industrial applications

A single or three phase asynchronous motors, or known a squirrel cage motors (SCMs) are represent one of generally using in many industrial applications. They are consuming further than half-percent of the total generated electrical energy. This motor is working at its full speed when it is attached to the main AC- supply. Therefore, speed control of asynchronous motor is necessary to industrial applications that require changeable flow control of fluid (air, water and chemical liquid streaming). There are many methods to control the speed of motors, such as changing the stator number of poles, controlling supply voltage, addition series reactor or resistances. The modern method is Volt per Hertz, or scalar control this method applied by changing voltage and frequency of three-phase supply, or by making a V/f equal to a constant value in this method a large amount of energy can be saved. In this study, analysis and practical implemented to variable voltage Variable Frequency Drive or called a VFD. The model enables an exception of a large amount of energy, when connected to control speed of Induction motor. A new simplified method for implemented of an AC Drive system with a moderate price for components was proposed. This method totally based on assembling overall components of AC-Drive. The advantage of this design is simplicity, robustness and ease of tuning as well as manufacturing due to these advantages. This design is very suitable for real time applications as motor speed controller. The experimental results obtained show that design helps to preserve a large amount of energy to the power grid, by a limited starting current of the motor as well, eliminating a voltage flicker at starting and reducing dissipating power during running in long period. Results verified experimentally.

Vibration Control of a Floating Raft System by Synchrophasing of Electrical Machines: An Experimental Study

This paper describes an experimental investigation into the vibration control of multiple electrical machines installed on a large-scale floating raft system. Vibration transmission to a flexible hull-like structure that supports the floating raft is controlled by adjusting the phases of the electrical power supply to the machines—a technique known as synchrophasing. Each machine is driven by a phase asynchronous motor and has two counter rotating shafts with adjustable eccentric masses, which allows the dynamic force generated by each machine to be set independently. Up to four rotating machines are considered. A genetic algorithm is used in the search for the optimum relative phases between each machine, because it is impractical to carry out an exhaustive search of the huge number of possible phase combinations. It is demonstrated that vibration control using synchrophasing is feasible in a marine environment, and can achieve significant vibration reduction, by simply adding some sensors and a control system. Reduction in the total transmitted vibration, as measured by the sum of the squared accelerations from 22 error sensors on the hull-like structure, was found to be up to 13 dB, and vibration reduction at higher harmonic frequencies was found to be up to 51 dB.

Detecting broken rotor bars in induction motors with model-based support vector classifiers

We propose a methodology for testing the sanity of motors when both healthy and faulty data are unavailable. More precisely, we consider a model-based Support Vector Classification (SVC) method for the detection of broken bars in three phase asynchronous motors at full load conditions, using features based on the spectral analysis of the stator's steady state current (more specifically, the amplitude of the lift sideband harmonic and the amplitude at fundamental frequency). We diverge from the mainstream focus on using SVCs trained from measured data, and instead derive a classifier that is constructed entirely using theoretical considerations. The advantage of this approach is that it does not need training steps (an expensive, time consuming and often practically infeasible task), i.e., operators are not required to have both healthy and faulty data from a system for checking it. We describe what are the theoretical properties and fundamental limitations of using model based SVC methodologies, provide conditions under which using SVC tests is statistically optimal, and present some experimental results to prove the effectiveness of the suggested scheme.

Torsional stress analysis of the squirrel-cage rotor for three phase asynchronous motors

The paper aims to determine the torsional stress occurring in the rotor's shaft of the three phase asynchronous motors for a given rotational speed of the rotor. The three phase asynchronous motor is started using the main starting variants, each variant having its own torque characteristic which produces a certain maximum shear stress. The model uses several hypotheses regarding the geometry of the domain, the dynamic behavior, the friction phenomenon and the mass of the shaft which is disregarded in a model and it is considered in a more accurate model. The maximum shear stress is produced by the shock which occurs in the starting process of the motors. This maximum stress may lead to the failure of the rotor either because it breaks, or because of the fatigue of the material produced by frequent starting of the motor. Information resulted from this study are useful for the selection of the appropriate material, of the according geometry of the design and elaboration of the specifications for the in-service use of the motor.This theoretical study will be followed by the development of more accurate models which will also include experimental studies employed to calibrate the theoretical models and to verify their accuracy.

Modeling and Simulating of Frequency Conversion Soft Start System Based on SPWM

Since over large starting current makes an instant giant grid voltage drop and contacting with current spark can damage the starting device when three phase asynchronous motor is directly started, in order to reduce the impact on the grid and the motor caused by the over large starting current, the present disclosure provides a frequency conversion soft start system based on SPWN. Control system generates IGBT controlled by SPWM pulse control using the regular sampling II method, thus achieving an AC infinitely approaching to a sine wave to open-loop control the motor and implement soft start. The method of frequency conversion soft start based on SPWM may implement a smooth start of the motor with lesser starting current and larger starting torque, thereby largely reducing the impact on the grid voltage and the motor. The experimental results showed that the method of frequency conversion soft start based on SPWM effectively reduces the starting current and implements the motor’s smooth start.

Research on Reactive Power Compensation Issues in Process of Motor Soft Start

Abstract In order to deal with the problems of large start current and low power factor that caused by threephase asynchronous motors start, a new integrative method of soft start and dynamic reactive power compensation is proposed. In this paper, the rule of power factor vs. speed in a three phase asynchronous motor is investigated and the reason of such rule is analyzed. Aiming at the large start current problem, soft start method based on auto-transformer and magnetic control reactor (ATMCR) is invented. This method can further reduce start current from gird. Aiming at the low power factor problem, the method of thyristor switched capacitor (TSC) is used to dynamically compensate reactive power. Simulation and experimental results can prove that the integrative method can effectively deal with the problems of large start current and low power factor.

MATLAB Based Model for Analysis of the Effect of Equivalent Circuit Parameters of an Asynchronous Motor on its Dynamic Characteristics

A poly phase asynchronous motor - for instance, an induction motor finds application in several areas due to its reliability, robustness, low maintenance and a very competitive pricing. This paper addresses the impact of stator and rotor parameters of an induction motor in its dynamic characteristics using a MATLAB / SIMULINK based model. This analysis helps in determining the stator and rotor circuit resistance and inductances to reduce steady state time and minimize jerks during starting of the motor.

Single phase inverter design based on selective harmonic elimination method

Minimization of harmonic distortions in voltage source inverters’ output wave form is very important. In this paper, a single phase inverter design that can change the operating frequency between 5 Hz – 50 Hz to achieve the keeping the voltage/frequency ratio (V/f) as constant during single phase asynchronous motor driving is presented. For the aim of minimizing the voltage harmonics, pulse width modulation (PWM) based selective harmonic elimination method (SHEM) is used in the design. Via this method, 3., 5., 7., 9., 11. and 13. harmonic components of the inverter output voltage are eliminated while regulating the amplitude of the main harmonic component. A practical application circuit is installed for the proposed design. The obtained results have shown that the proposed design is efficient in reducing of harmonic distortions.

Research and Development of High Efficiency & Energy Saving Series, High-Voltage & Flame Proof Three Phase Asynchronous Motor for Fan

In order to save energy, decrease the loss and improve the technology level of high voltage flame proof three phrase asynchronous motor for fan, the condition, problem and development trend of the motor are studied in the paper. The motor structure, wind path system, electromagnetic scheme, insulation structure, electrical explosion-proof structure are improved, and non electric explosion-proof theory and low noise design are firstly applied in the research and development of motor. The efficiency of the motor is improved 2% by the method of optimizing the structure of motor and improving the making technology. The new motor not only has high efficiency and advanced and reliable structure, but also is safety in use, convenience in maintenance, has better social and economical benefits and better market prospect.

Study on method of Energy-Saving and Efficiency Improvement of Flame Proof Three Phase Asynchronous Motor for Fan

All kinds of factors affecting the efficiency of three phase asynchronous motor are studied, the methods of energy-saving and efficiency improvement of flame proof three phase asynchronous motor for fan are analyzed form the aspect of calculation of electromagnetism, selection of material, design of wind path, machining process etc, the practical optimizing methods are put forward and are verified through the product. The experiment show that the efficiency of the motor designed according to this method has improved greatly. So these methods provide some reference for the design of flame proof three phase asynchronous motor for fan. Other methods that could be used to saving energy are also analyzed in theory in the paper, which offer some reference for the enterprise using mining flame proof fan to seek the method of energy-saving and efficiency improvement.

Study on Magnetic Field Effect of AC Motor

This paper analyzed the establishment of pulsating magnetic field for the single-phase asynchronous motor. Put forward a theory of pulsating magnetic field. A discussion of the method is given by graphical analysis of the magnetic field and mathematical derivation of MMF. The analysis is included the magnetic field effect of the three phase asynchronous motor and the two phase AC servo motor. That is synthesized by single-phase pulsating magnetic field based on some way.

Multiphase electromagnetic stirring of low conducting liquids

PurposeTo produce a controlled stirring in a low conducting liquid thanks to a new kind of multiphase inductor.Design/methodology/approachAn experimental pilot consisting of a cylindrical salt water pool surrounded by an innovative multiphase inductor configuration, based on the single phase asynchronous motor principle, is setup. The maximum bulk stirring velocities are measured and compared with the estimate by numerical modelling.FindingsShows the possibility of controlling the stirring of a low conducting liquid thanks to a multiphase inductive system. The corresponding measurement results give a significant bulk velocity of a few centimetres per second.Practical implicationsThis new kind of multiphase inductor, working with a single phase induction generator, seems a promising way to produce a controlled stirring in low conducting media which cover a large range of induction applications.Originality/valueSuch an innovative inductor configuration has already been tested successfully for metal alloys stirring in the middle frequency area. In this paper, an extension of this kind of multiphase inductive system for electromagnetic stirring of low conducting liquids like electrolytes in the high frequency area is presented.

Fuzzy logic based static VAR compensators for enhancing the performance of synchronous and asynchronous motor loads

The paper presents a simple yet powerful fuzzy logic based static VAR compensator (FLSVC) applied to an industrial power network consisting of three phase synchronous and asynchronous motor loads. In the proposed fuzzy logic controller (FLC), the speed and acceleration variations of a specific machine are taken as the inputs. To demonstrate the effectiveness and capabilities of the employed FLSVC, several non-linear time-domain digital simulation tests are performed. The results show that over a wide range of operating conditions and disturbances, the FLSVC improves remarkably the voltage profile and the overall dynamic performance.