scholarly journals Development and thermal modeling of an induction machine

2019 ◽  
Vol 8 (4) ◽  
pp. 500
Author(s):  
Oti Stephen Ejiofor ◽  
Ugwu Justin ◽  
Nnadi Damian Benneth ◽  
Ogbuefi Uche
Keyword(s):  
Induction Motor ◽  
Reference Frame ◽  
Temperature Rise ◽  
Thermal Model ◽  
Research Work ◽  
Induction Machine ◽  
Operating Conditions ◽  
Electrical Behavior ◽  
Stator Current ◽  
Physical Measurements

In induction machines, the major concern is the temperature rise since it determines the maximum loading, in an attempt to avoid insula-tion deterioration and eventual loss of motor life. The effect of excessive heat in the motor stator and rotor windings and the stator mag-netic circuit can degrade the developed performance of the machine and also affect the motor loading and life span if not dispensed properly. This research work examines the thermal model for estimating the stator and rotor temperatures in cage induction motor. A state-variable model of the induction is used. The twin-axis stator reference frame is used to model the motor’s electrical behavior, because physical measurements are made in this reference frame. The thermal model is derived by considering the power dissipation, heat transfer and rate of temperature rise in the stator and rotor. The non-linear equations for electrical behavior of the motor and the thermal state equations for the stator and the rotor are solved using the MATLAB/Simulink blocks. This is to give room for the determination of the temperature of the stator and rotor windings inside the induction machine so as to evaluate the thermal stability of the induction motor and to check whether the insulation of the copper windings is sufficient at different operating conditions. It was found out from the thermal model analysis that the temperature of the stator and rotor windings increases due to stator and rotor copper losses which depend on the stator current. As the stator current is increased by increasing the torque, the temperature of each element is consequentially made to increase.  

Model of Vector Controlled Induction Drive

2009 ◽  
Vol 147-149 ◽  
pp. 149-154
Author(s):  
Roma Rinkeviciene ◽  
Andrius Petrovas
Keyword(s):  
Induction Motor ◽  
Reference Frame ◽  
Real Variable ◽  
Flux Linkage ◽  
Current Channel ◽  
Stator Current ◽  
Synchronous Reference Frame ◽  
Rotor Flux ◽  
Drive Model ◽  
Motor Model

The paper presents the model of vector controlled induction motor. Induction motor model is carried out in reference frame, fixed on stator. Elaborated model of the drive is suitable for investigation dynamics because output signals appear as real currents, flux linkages and other variables. Vector control law model is implemented for variables in synchronous reference frame; therefore controller operates with transformed variables. Structure of designed model reflects the real variable speed drive. Model of vector controlled induction drive comprise model of induction motor, feedback signals and blocks as well as speed and flux reference blocks and controllers for producing motor supply signals. Feedback blocks are used for calculation stator current vector in the rotor flux linkage reference frame. For flux and speed control are designed lag controllers. Between advantages of that model is additional simulation of current channel law.

Proportional Integral Estimator of the Stator Resistance for Direct Torque Control Induction Motor Drive

2017 ◽  
Vol 8 (4) ◽  
pp. 1631
Author(s):  
Jagdish Gangadharrao Chaudhari ◽  
Sanjay Bhauraoji Bodkhe ◽  
Mohan V. Aware
Keyword(s):  
Induction Motor ◽  
Estimation Error ◽  
Direct Torque Control ◽  
Estimation Method ◽  
Operating Conditions ◽  
Torque Control ◽  
Proportional Integral ◽  
Stator Current ◽  
Current Estimation ◽  
Stator Resistance

In this paper, an improved proportional integral stator resistance estimation for a direct torque controlled induction motor is proposed. This estimation method is based on an on-line stator resistance correction regarding the variations of the stator current estimation error. In fact, the input variable of the PI estimator is the stator current estimation error. The main idea is to tune accurately the stator resistance value relatively to the evolution of the stator current estimation error gradient to avoid the drive instability and ensure the tracking of the actual value of the stator resistance. But there is an unavoidable steady state error between the filtered stator current modulus and its estimated value from the dq model of the machine which is due to pseudo random commutations of the inverter switches. An offset has been introduced in order to overcome this problem, for different speed command values and load torques. Simulation results show that the proposed estimator was able to successfully track the actual value of the stator resistance for different operating conditions

scholarly journals Improving the energy efficiency of electric drives for auxiliary units of traction rolling stock

2021 ◽  
Vol 2131 (4) ◽  
pp. 042085
Author(s):  
T S Titova ◽  
A M Evstaf’ev ◽  
A A Pugachev
Keyword(s):  
Energy Efficiency ◽  
Control Systems ◽  
Induction Motor ◽  
Induction Machine ◽  
Rolling Stock ◽  
Electric Drives ◽  
Operating Modes ◽  
Stator Current ◽  
Power Loss Reduction ◽  
Rotor Winding

Abstract The review of technical solutions and schematic characteristics of auxiliary drives for traction vehicles has shown that the most rational variant is an electric drive with an induction machine. Given the operating modes of the auxiliary drives and the share of their power consumption in the total locomotive power, the task of using scalar control systems for induction machines becomes relevant. Based on a mathematical model describing the dynamic energy conversion processes in the T-shape substitution circuit of an induction motor, taking into account stator steel losses and current displacement effects in the rotor winding and saturation along the main magnetic path, possibilities for reducing stator current have been investigated. In order to improve the energy efficiency of electric drives two variants of control system have been proposed. One based on search method of self-tuning to the stator current minimum and the other - on maintaining the power factor of induction motor at the level that ensures equality of active and reactive components of stator current. The hardware and software requirements for implementing control systems have been analysed. Modelling using Matlab has shown that both control systems work - power loss reduction can be as low as 50% and as high as 60% in certain modes.

scholarly journals Speed Sensorless Control of Six-Phase Asynchronous Motor Drive

2017 ◽  
Vol 4 (1.) ◽  
Author(s):  
Z.M.S. Elbarbary
Keyword(s):  
Induction Motor ◽  
High Performance ◽  
Asynchronous Motor ◽  
Estimation Method ◽  
Motor Drives ◽  
Operating Conditions ◽  
Speed Estimation ◽  
Speed Sensorless ◽  
Stator Current ◽  
Current Error

Multi -phase ac motor drives are nowadays considered for various applications, due to many advantages that they offer when compared to three-phase motors. Cancellation of mechanical position or speed sensors at the motor shaft have the attractions for adjustable speed drives of induction motor to reduce the cost and increase the reliability. To replace the sensor, information of the rotor speed is extracted from measured stator currents and voltages at motor terminals. This paper investigates speed estimation method using model reference adaptive system (MRAS) to improve the performance of a sensorless vector controller of six-phase induction motor (IM). In the proposed method, the stator current is used as the state variable to estimate the speed. Since the stator current error is represented as a function of the first degree for the error value in the speed estimation, the proposed method provides fast speed estimation and is also, more robust to variations in the stator resistance, compared with other MRAS methods. Consequently, this method can improve the performance of a sensorless vector controller in a low speed region and at zero-speed. The proposed method is verified by simulation using the Matlab/Simulink package. The performance of the proposed system is investigated at different operating conditions. The proposed controller is robust and suitable for high performance six-phase induction motor drives. Simulation results validate the proposed approaches.

scholarly journals Thermal Modelling and Analysis of A 10HP Induction Machine Using the Lumped Parameter Approach

2021 ◽  
Vol 13 (6) ◽  
Author(s):  
Oti S.Ejiofor ◽  
◽  
Awah Chukwemeka ◽  
Chibuzo Nnonyelu ◽  
Ogbonnaya I.Okoro ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Life Span ◽  
Thermal Model ◽  
Research Work ◽  
Induction Machine ◽  
Thermal Modelling ◽  
Thermal Limits ◽  
Lumped Parameter ◽  
Parameter Approach ◽  
Different Parts

The essence of this research work is to develop a thermal model for an induction machine that will enable the prediction of temperature in different parts of the machine. This is very important first to the manufacturer or designer of an induction machine because with these predictions one can decide on the insulation class limits the machine belongs to. Also modern trends in the construction of machines is moving in the direction of making machines with reduced weights, costs and increased efficiency. In order to achieve this, the thermal analysis becomes very crucial in deciding on what types of insulators and other materials that would be used to make these machines. In industries, the knowledge of the thermal limits of machines if well utilized increases the life span of the machines and reduces downtime; thereby increasing production and profit. Specifically, this paper (i) predicted the temperature limits of the induction machine and its components, (ii) developed an accurate thermal model for an induction machine, (iii) predicted the temperature in different parts of the induction machine using the thermal model and software program and lastly (iv) investigated how the machine symmetry is affected by the nodal configuration.

scholarly journals Convolutional Neural Network-Based Stator Current Data-Driven Incipient Stator Fault Diagnosis of Inverter-Fed Induction Motor

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1475 ◽  
Author(s):  
Maciej Skowron ◽  
Teresa Orlowska-Kowalska ◽  
Marcin Wolkiewicz ◽  
Czeslaw T. Kowalski
Keyword(s):  
Neural Network ◽  
Fault Diagnosis ◽  
Convolutional Neural Network ◽  
Induction Motor ◽  
Current Data ◽  
Operating Conditions ◽  
Stator Winding ◽  
Stator Current ◽  
Short Circuits ◽  
The Impact

In this paper, the idea of using a convolutional neural network (CNN) for the detection and classification of induction motor stator winding faults is presented. The diagnosis inference of the stator inter-turn short-circuits is based on raw stator current data. It offers the possibility of using the diagnostic signal direct processing, which could replace well known analytical methods. Tests were carried out for various levels of stator failures. In order to assess the sensitivity of the applied CNN-based detector to motor operating conditions, the tests were carried out for variable load torques and for different values of supply voltage frequency. Experimental tests were conducted on a specially designed setup with the 3 kW induction motor of special construction, which allowed for the physical modelling of inter-turn short-circuits in each of the three phases of the machine. The on-line tests prove the possibility of using CNN in the real-time diagnostic system with the high accuracy of incipient stator winding fault detection and classification. The impact of the developed CNN structure and training method parameters on the fault diagnosis accuracy has also been tested.

Short Circuit between Turns in Stator Winding of Induction Machine Fault Detection and Diagnosis

2013 ◽  
Vol 416-417 ◽  
pp. 565-571 ◽  
Author(s):  
Youcef Soufi ◽  
Tahar Bahi ◽  
H. Merabet ◽  
S. Lekhchine
Keyword(s):  
Induction Motor ◽  
Low Cost ◽  
Short Circuit ◽  
Induction Machine ◽  
Fault Detection And Diagnosis ◽  
Operating Conditions ◽  
Stator Winding ◽  
Detection And Diagnosis ◽  
Abnormal Operating Conditions ◽  
Short Circuit Fault

The induction motor is one of the most used electric machines in variable speed system in the different field of industry due to its robustness, mechanical strength and low cost. Despite these qualities, the induction machine is subjected during its operation to a number of constraints of various natures (electrical, mechanical and environmental). This paper focuses on the diagnosis and the detection of the short circuit fault between turns in the stator winding of an induction machine, based on analyzing the evolution of the stator current in each stator phase, using tools based both on motor current spectral analysis and Park vector approach. A study by simulation was presented. The obtained results show that the considered methods can effectively diagnose and detect abnormal operating conditions in induction motor applications. Therefore, they clearly show the possibility of extracting signatures and the application of these techniques offered reliable and satisfactory results for the diagnosis and detection of such fault.

Discerning broken rotor bar failure from low-frequency load torque oscillation in DTC induction motor drives

2016 ◽  
Vol 40 (1) ◽  
pp. 279-286 ◽  
Author(s):  
Taner Goktas ◽  
Müslüm Arkan
Keyword(s):  
Induction Motor ◽  
Direct Torque Control ◽  
Induction Machine ◽  
Low Frequency ◽  
Motor Drives ◽  
Torque Control ◽  
Induction Motor Drives ◽  
Load Torque ◽  
Broken Rotor Bar ◽  
Stator Current

This paper proposes a method for separation of broken rotor bar failures from low-frequency load torque oscillation in direct torque control (DTC) induction motor drives by using vq voltage and iq current components’ spectra. The effect of load torque oscillation should be considered in induction motor drives for reliable broken bar fault detection. Induction machine drivers are run in DTC mode to control its torque and speed. In practice, the presence of load torque fluctuation may sometimes cause false positive alarms on stator current spectrum. However, discerning of broken rotor bar failure from low-frequency load variation for DTC drives remains unexplored. Experimental results show that by using the proposed method broken rotor bar failure can be reliably detected in the presence of low-frequency load torque oscillation in DTC induction motor drives.

scholarly journals New adaptive hysteresis band width control for direct torque control of induction machine drives

2020 ◽  
Vol 11 (4) ◽  
pp. 1908
Author(s):  
Arkan A. Kadum
Keyword(s):  
Induction Motor ◽  
Direct Torque Control ◽  
Induction Machine ◽  
Operating Conditions ◽  
Torque Control ◽  
Voltage Reference ◽  
Control Approach ◽  
Frequency Vectors ◽  
Stator Flux ◽  
Machine Drives

This paper presents a new adaptive hysteresis band control approach used in direct torque control (DTC) of the induction motor (IM) drives with the switching tables for the generation of PWM signals. Constant Hysteresis Direct torque control (CHB-DTC) method used the torque and stator flux errors to generate the stator voltage reference and frequency vectors for controlling the three-phase induction motor. The CHB-DTC gives better torque transient performance but it has large steady state ripples. To reduce torque and stator current ripples in CHB-DTC controlled induction motor drives a new adaptive hysteresis band control (AHB) approach is proposed, where the hysteresis band is adapted in real time with the stator flux and torque errors variation, instead of fixed bandwidth. Both classical CHB-DTC method and the proposed adaptive hysteresis band DTC (AHB-DTC) fed three induction motor have been simulated using Matlab/Simulink. The simulation results at different operating conditions over a wide speed range demonstrate the validity, effectiveness, and feasibility of the proposed scheme. The measurements showed that torque ripples were significantly decrease with the new AHB-DTC technique and better speed response in step up or down compared to the CHB-DTC.

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