Reliability Of Induction Motors Research Articles

Regression Based Performance Analysis and Fault Detection in Induction Motors by Using Deep Learning Technique

The recent improvements related to the area of electric locomotive, power electronics, assembly processes and manufacturing of machines have increased the robustness and reliability of induction motors. Regardless of the increased availability, the application of induction motors in many fields alleges the need for operating state supervision and condition monitoring. In other words, fault identification at the initial stage helps make appropriate control decisions, influencing product quality as well as providing safety. Inspired by these demands, this work proposes a regression based modeling for the analysis of performance in induction motors. In this approach, the feature extraction process is combined with classification for efficient fault detection. Deep Belief Network (DBN) stacked with multiple Restricted Boltzmann Machine (RBM) is exploited for the robust diagnosis of faults with the adoption of training process. The influences of harmonics over induction motors are identified and the losses are mitigated. The simulation of the suggested approach and its comparison with traditional approaches are executed. An overall accuracy of 99.5% is obtained which in turn proves the efficiency of DBN in detecting faults.

Diagnosis of Shaft Misalignment Fault by Piezoelectric Materials to Improve Reliability of Induction Motors

This paper proposes measures to improve the availability and the efficiency of induction motors in industry via the implementation of control shaft misalignment using a piezoelectric material. For this purpose, motors’ failures, which have been extracted from refurbishing and repair workshops, have been used. By performing a critical study and using Pareto analysis, the most frequent failures that have a purely negative effect on the availability and efficiency of induction motors, such as damaged bearings and windings caused by shaft misalignment, which is a common problem in rotating machinery have been identified. An analysis of the induction motor is conducted in order to investigate the waveform by testing the shaft misalignment. This process is performed using a steel shims kit. The vibration signals during machine operation under different misalignment severities are measured. The fast Fourier transform of the signal is generated using National Instruments packages and Matlab software. The experimental results on a 1.1 kW induction motor are analyzed and presented. This paper also shows how shaft misalignment negatively affects induction motor efficiency. The objectives of this applied research are multi-fold; it aims to diagnose machine vibration by piezoelectric materials, to increase the availability of motors, to reduce stopped time caused by misalignment failure, to minimize power consumption and to reduce maintenance costs by generating significant benefits to the company while protecting the environment.

Development of a device providing resource-saving start-up of induction motors under reduced voltage

Electromechanical and thermal transients at start-up of squirrel-cage induction motors in reduced voltage conditions are the object of research. One of the most troubled places in these processes is sufficient difficulty diagnosing of resource consumption of induction motors with heavy start-up in reduced voltage conditions and timely facilitation of such regimes with a view to resource saving. To determine the diagnostic parameters of starting modes for induction motors at reduce of supply voltage it is necessary to identify the dependence of start-up duration depending on the parameters of the «motor – working machine» system and their impact on the thermal insulation wear in motor during period after start-up. Therefore, the main way to increase the operational reliability of induction motors is to develop technical device for diagnostics of additional thermal insulation wear in induction motor. We use such methods as: analysis method and mathematical modeling method. It is grounded that pulse of squared starting current can take as diagnostic parameter of additional thermal insulation wear of induction motor. Investigation of thermal insulation wear shows that the thermal transient at the start-up is adiabatic. Main thermal insulation wear is during period after start-up. The dependence of additional thermal insulation wear on the pulse of squared electric current of induction motor allows to select pulse set point of squared starting current of proposed device, which will facilitate the starting mode of the motor. A structural diagram of the device for diagnostics of additional thermal insulation wear in squirrel-cage induction motor during period after start-up is proposed.

The use of a special software for induction motor diagnostics in the diamond industry

The field of induction motor application in the diamond industry has considerably increased due to the transition to the underground mining method. This article is devoted to the research the induction motor diagnostic technique in the diamond industry using special software. The practice shows that unreliability of induction motors causes some serious economic losses related to the expenses on premature maintenance and idle time. This article is devoted to the research of diagnostic technique of induction motors in the diamond industry using a special software. The article presents some data obtained in the course of the research conducted at an industrial site of the diamond company “ALROSA” in Mirny using the vibration-based diagnostics. Thus, based on the analysis of the findings some recommendations concerning the improvement of maintenance and servicing system have been given. The use of these recommendations allows assessing the operational reliability of induction motors in the diamond industry, minimizing the risk of sudden failures and reducing the maintenance and repair expenses.

Study of electromechanical and thermal transients during starting of induction motors

This article presents the results of analytical studies of electromechanical and thermal transients during starting of induction motor with cage rotor in conditions of low voltage. The aim of the research is improving the operational reliability of induction motor with cage rotor in conditions of low voltage by development of technical devices for diagnostics based on theoretical foundations of electromechanical and thermal transients at starting. As a result of the research the theory of transient electromechanical and thermal processes in induction motor with cage rotor in conditions of low voltage is found a further development. For the first time it is proposed the starting mode evaluation parameter of system "induction motor – working machine" – the ratio of the moment of inertia of the system to the nominal moment of induction motor. For the first time it is grounded the parameter of diagnosing transient thermal processes at starting of induction motor in conditions of low voltage – extra thermal insulation depreciation in the period after starting. For the first time it is grounded the criterion of extra thermal insulation depreciation in the period after starting – squared power momentum of inrush current, which can be taken as a diagnostic parameter. Investigation of thermal insulation depreciation showed that the thermal transient at the start is adiabatic. Main thermal insulation depreciation is accounted for period after starting. The dependence of extra thermal insulation depreciation on squared momentum of inrush current allows selecting set point value of squared power momentum of inrush current of proposed device, which will facilitate the starting mode of the motor.

Design of high temperature induction motor for application in sodium cooled fast reactor control system

Prototype Fast Breeder Reactor (PFBR) employs induction motors of various power ratings in high temperature ambient and sometimes corrosive atmosphere. Safe operation of the reactor depends on robustness and reliability of induction motors in its critical components. Safety related systems such as shutdown and online inspection systems, utilize induction motors as actuators in their mechanisms. Since external cooling is not permitted in control and inspection motors, special design of motors is required to withstand high temperatures. This paper deals with design, analysis, fabrication and testing of a compact 50 W, three phase induction motor, suitable for operating up to 250 °C ambient with winding temperature withstand capability up to 550°C. The designed motor was analyzed with two dimensional Finite Element Model (FEM) code FEMM to study the torque slip characteristics and magnetic flux density patterns in stator and rotor.

Assessing the reliability of induction motors in gantry cranes

Mathematical models and software have been developed for assessing the reliability of induction motors in gantry cranes. On that basis, the reliability of the stator and rotor windings and the entire motor may be quantitatively determined. Estimates of the mean life and probability of fault-free operation are obtained for induction motors used in all gantry-crane drives. The results may be used in comparative calculations and also in the design, manufacture, and operation of crane motors.