scholarly journals Modeling of overloads of raising mechanism in metallurgical overhead cranes

2019 ◽  
Vol 62 (8) ◽  
pp. 646-651
Author(s):  
V. V. Varlamov ◽  
M. V. Kipervasser ◽  
A. V. Gerasimuk
Keyword(s):  
Electric Motor ◽  
Asynchronous Motor ◽  
Main Idea ◽  
Support Surface ◽  
Overhead Crane ◽  
Stator Current ◽  
Study Results ◽  
Sequential Solution ◽  
Load Separation ◽  
Emergency Mode

Electromechanical processes occurring when the load is lifted by an overhead crane are considered. The main idea of the work is to identify emergency mode (crane overload) by a method based on control of stator current of lift motor. To obtain stator current diagrams of electric motor, mathematical model of overhead crane (three-mass circuit) has been developed, which includes equations describing elastic properties of crane beams and its rope. A system of (α, β) coordinates, fixed relative to electric motor stator, is adopted to describe the drive asynchronous motor. Lifting cycle is considered as sequence of three steps: choice of the rope “slack”; rope tension; separation of cargo lifting. For each stage, a system of differential equations has been compiled describing motion of masses of overhead crane elements and electrical parameters of electric motor. Initial and boundary conditions for each of the stages were determined. Preliminary transformations of the system of equations to their solution by numerical methods and subsequent modeling of stages of lifting loads were carried out for different weights. Sequential solution of three boundary value problems allows obtaining values of stator currents at time of load separation. Diagrams of stator phase currents of an electric motor were obtained for loads of different mass. Simulation results indicate the presence of fixable difference in magnitudes of stator currents after the load is separated from the support surface. On basis of the developed model and the study results, a functional diagram of crane overload protection device is proposed and its principle of operation is described. It consists in controlling lifted load mass and stator current when liftingthe load. Conclusion is made about feasibility and effectiveness of monitoring electrical values of lifting motor for development of overhead crane protection against overloads. Effectiveness of the proposed system was evaluated.

scholarly journals INVESTIGATION OF THE DYNAMICS OF AN OVERHEAD CRANE LIFTING PROCESS IN A VERTICAL PLANE

Transport ◽  
2005 ◽  
Vol 20 (5) ◽  
pp. 176-180 ◽  
Author(s):  
Marijonas Bogdevičius ◽  
Aleksandr Vika
Keyword(s):  
Dynamic Behaviour ◽  
Equations Of Motion ◽  
Asynchronous Motor ◽  
Linear Equations ◽  
Vertical Plane ◽  
Overhead Crane ◽  
Dynamic Forces ◽  
Planet Gear ◽  
Linear Equations Of Motion ◽  
Non Linear Equations

The paper analyses the dynamic behaviour of supporting structure of an overhead crane during the operation of a hoisting mechanism. The crane is expected to operate with a hook and to carry 50 kN of weight. The electric hoist consists of an asynchronous motor with a magnetic brake, a two‐level planet gear, a load drum and an upper block. Non‐linear equations of motion of a crane hoisting mechanism are derived. Real dynamic forces and their influence on the hoisting crane behaviour are obtained. Numerical results of the crane are derived considering two hoisting regimes during the operation of the hoisting.

scholarly journals Comparing hydraulic and electromechanical drives by electric motor’s power

2019 ◽  
Vol 294 ◽  
pp. 01002
Author(s):  
Otto Grigorov ◽  
Galyna Anishchenko ◽  
Evhen Druzhynin ◽  
Vsevolod Strizhak ◽  
Mariana Strizhak ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Electric Motor ◽  
Asynchronous Motor ◽  
Hydraulic Drive ◽  
Operation Time ◽  
Operating Conditions ◽  
Positive Displacement ◽  
Work Cycle

The authors have made the analysis of energy consumption by positive-displacement hydraulic drive and asynchronous motor with phase rotor in the course of crane mechanisms operation at all stages of motion: acceleration, movement at nominal or intermediate speed, and deceleration. There have been determined and compared equivalent capacities per work cycle for electric and hydraulic drives of crane mechanisms depending on operating conditions group and operation time. There has been justified the decrease of rated capacity of electric motor of crane mechanisms’ hydraulic drive as compared with the case of applying asynchronous motor with phased rotor for the same mechanisms.

Determination of Important Parameters and Technical Characteristic for Welding Fumes Index Development by Using QFD Approach

2013 ◽  
Vol 315 ◽  
pp. 744-748
Author(s):  
Azian Hariri ◽  
Abdul Mutalib Leman ◽  
Mohammad Zainal M. Yusof
Keyword(s):  
Quality Function Deployment ◽  
Health Hazard ◽  
Main Idea ◽  
Workplace Safety ◽  
Technical Characteristic ◽  
Welding Fumes ◽  
System Effect ◽  
Safety And Health ◽  
Study Results

This paper discussed on the determination of important parameters and technical characteristic for the development of a welding fumes index by using Quality Function Deployment (QFD) approach. Welding fumes index is developed with the objective to enhance the welding workplace safety and health. Index simplifies complex health-hazard issues of welding fumes to be comprehended easily by the employees. Questionnaires on welder desire to know the various welding fumes health effects that exist in their workplace were distributed among welders of a selected automotive assembly lines in the state Pahang, Malaysia, during a pilot case study. Results of the questionnaires show that all the customer requirements (irritants effect, sensitizer effects, respiratory system effect, systemic toxin effect, reproductive toxins effect, carcinogen effect, mixture effect) were equally important to the welders. The relationship between the customer (welder) requirement and technical characteristic were established whereby important technical characteristics were shortlisted. Development of welding fumes index according to employees demand will increase the knowledge and awareness on occupational safety and health among employees. The paper provides the main idea on development of welding fumes index taking into consideration the needs of the customer i.e. welder.

Wavelet Transform for Starting Characteristics of Three-Phase Cage Asynchronous Motor

2011 ◽  
Vol 347-353 ◽  
pp. 2987-2990
Author(s):  
Yuan Yuan Li ◽  
Qi Zhong Liu ◽  
Chao Gang Yu
Keyword(s):  
Wavelet Transform ◽  
Performance Test ◽  
Harmonic Wave ◽  
Asynchronous Motor ◽  
Time Frequency ◽  
First Order ◽  
Stator Current ◽  
Electric Machinery ◽  
Three Phase ◽  
Starting Characteristics

In electric machinery performance test, tooth harmonic time-frequency characters of first order of three-phase cage asynchronous motor are most important. The MATLAB software is used to make model and simulate the starting characteristic of asynchronous motor in this article, while the stator current signal of starting motor is de noised by wavelet transform. Through decomposition and reconstruction of wavelet transform, the amplitude of fundamental and harmonic wave in de noising stator current can be reduced, and then the tooth harmonic of first order of starting rotor is extracted. Using the excellent time-frequency analyzing characters of wavelet package transform, the tooth harmonic time-frequency curve is fitted.

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 Adaptive Scheme for Detecting Induction Motor Incipient Broken Bar Faults at Various Load and Inertia Conditions

Sensors ◽  
2022 ◽  
Vol 22 (1) ◽  
pp. 365
Author(s):  
Mohamed Esam El-Dine Atta ◽  
Doaa Khalil Ibrahim ◽  
Mahmoud Gilany ◽  
Ahmed F. Zobaa
Keyword(s):  
Main Idea ◽  
Threshold Value ◽  
Operating Conditions ◽  
Noisy Environment ◽  
Noisy Environments ◽  
Variable Loading ◽  
Protection Scheme ◽  
Stator Current ◽  
Fault Severity ◽  
Frequency Components

This paper introduces a novel online adaptive protection scheme to detect and diagnose broken bar faults (BBFs) in induction motors during steady-state conditions based on an analytical approach. The proposed scheme can detect precisely adjacent and non-adjacent BBFs in their incipient phases under different inertia, variable loading conditions, and noisy environments. The main idea of the proposed scheme is monitoring the variation in the phase angle of the main sideband frequency components by applying Fast Fourier Transform to only one phase of the stator current. The scheme does not need any predetermined settings but only one of the stator current signals during the commissioning phase. The threshold value is calculated adaptively to discriminate between healthy and faulty cases. Besides, an index is proposed to designate the fault severity. The performance of this scheme is verified using two simulated motors with different designs by applying the finite element method in addition to a real experimental dataset. The results show that the proposed scheme can effectively detect half, one, two, or three broken bars in adjacent/non-adjacent versions and also estimate their severity under different operating conditions and in a noisy environment, with accuracy reaching 100% independently from motor parameters.

scholarly journals Speed Regulation and Control of Inverter Fed Induction Motor Drives Using Controllers (PI, PID)

2020 ◽  
pp. 7-14
Author(s):  
Piyush Kumar Ojha ◽  
Eeshan Amiy ◽  
Apurv Nihal Bhagat ◽  
Sumit Kumar
Keyword(s):  
Induction Motor ◽  
Electric Motor ◽  
Asynchronous Motor ◽  
Motor Drives ◽  
Variable Speed ◽  
Induction Motor Drives ◽  
Matlab Simulink ◽  
Speed Regulation ◽  
And Control ◽  
Selection Of

An induction (or asynchronous) motor is an AC electric motor in which runs at the rated condition but there is indeed of variable speed of motor. There are numbers of methods available for speed control, but there is need for selection of proper controller for obtaining the desired result. Simulation was done in the MATLAB Simulink software.

Sign in / Sign up

Export Citation Format

Share Document