Industrial Electric Motors Research Articles

Evaluation of the energy saving potential in electric motors applying a load-based voltage control method

This paper studies the viability of energy savings in electric motors by adjusting the voltage according to load in motors that operate under significant load variations during their work cycles. The laboratory test program used a 1.1 kW electric motor to compare its measured efficiency operating without voltage control with the load-based voltage control method results. A neural network was developed, and a time series generator was used to model the motor and estimate the results of applying the method in its useful life in the load behavior of three operating regimes. The results show an energy saving potential of 2 %–5.2 % using the load-based voltage control method in motors operating with a load factor of less than 40 % during the simulated motor life cycle for the three operating regimes. Also, the economic feasibility of implementing the load-based voltage control method was evaluated on three industrial electric motors. Results indicated potential annual savings between $1227 and USD 1,549, with a projected investment payback period of less than three and a half years.

ПОВЫШЕНИЕ ЭНЕРГОЭФФЕКТИВНОСТИ ПРОМЫШЛЕННЫХ ЭЛЕКТРОДВИГАТЕЛЕЙ

The article is devoted to the study of methods for improving the energy effi-ciency of industrial electric motors, modern technologies that reduce energy consumption and increase productivity are considered. The key factors affecting energy efficiency are described, such as the use of high-efficiency materials, the use of frequency-controlled drives (VFDs), the replacement of outdated equipment and modernization methods. Special attention is paid to the economic and environmental benefits of implementing energy-efficient solutions, as well as the importance of energy audit and monitoring the condition of electric motors for their optimal op-eration.

Diagnostics and predictive maintenance of industrial electric motors

Automatic continuous or periodic control is the most promising method of diagnosing electric motors in productionnowadays. Itis aimed at predicting breakdowns and the remaining useful lifetimeof motors. However, research in this arearemains purely theoretical and eitherfocuses on very narrow problemsor providestoo superficial overview.Consequently,manual control devices orpartially automated devices are mainlyusedin practice[1]. In view of this, there is great interest in the development of a software method for predictive maintenance of electric motors. In this research recurrent neural networks with long short-term memory layers (LSTM-layers)are investigated due to their abilityto effectively model sequential data and learn complex dependencies [2].

Experimental Investigation of a Low-Temperature Three-Circuit Cooling System for an Electric Motor under Varying Loads

This study investigates a low-temperature three-circuit cooling system for a 55 kW industrial electric motor. The cooling system provides an increase of the power-to-dimension ratio by 63%, together with an improvement in motor performance. The three-circuit cooling system includes water cooling of the housing and stator and air-cooling of the motor’s interior. The test results show that the motor efficiency was maintained in the range between 92.5 and 94.5%, with respect to the motor’s power. With power increases up to 90 kW, a winding temperature of 67 °C was observed during three hours of operation. This advancement is particularly valuable for vehicles, ships, and aircraft applications, where maximizing power within limited space is crucial. An analysis of the experimental data showed that the cooling system operates at an average efficiency of 79.2%, indicating that roughly 20% of heat was accumulated in the rotor. This leads to a gradual temperature rise, particularly in the rotor, posing a risk of overheating and failure during motor overloads above 90 kW. Enhancing the cooling efficiency within the motor’s interior can be achieved by incorporating extra heat exchangers, implementing evaporative heat transfer, and employing water-cooling circuits at lower temperatures. This, in turn, can boost the electric motor’s power-to-dimension ratio.

Development of an energy harvesting system based on a thermoelectric generator for use in online predictive maintenance systems of industrial electric motors

In the era of the Fourth Industrial Revolution, improvements in maintenance routines for industrial electric motors are continuously being made, allowing for the development of Predictive Maintenance (PdM) Online. PdM can be executed by employing small embedded systems that are affixed to electrical machines. Although a small-capacity battery can effectively power an ultra-low consumption sensor, the extensive use of batteries can contribute to increased environmental pollution. An effective approach to obviate the necessity for batteries is to employ energy-harvesting techniques from electric motors. In this regard, this paper aims to contribute to advancements in research concerning the harvesting of thermoelectric energy from industrial electric motors to create a self-sustaining Internet of Things (IoT) device. To achieve energy autonomy, the construction of a mechanical coupling for the attachment of Thermoelectric Generators (TEGs) was proposed, along with the maximization of small TEG production and the optimization of the electronic circuit for energy management. The mechanical prototype for affixing TEGs to low-power electric motors enabled a maximization of the generated energy by the TEGs, and the electronic circuit optimization process resulted in the generation of 370.10 μW, exceeding the energy requirements for making the IoT device self-sustaining by 54.21%.

Development of an Electromagnetic Energy Harvesting System Based on a Current Transformer for Use in Industrial Electric Motors

Development of an Electromagnetic Energy Harvesting System Based on a Current Transformer for Use in Industrial Electric Motors

Designing a voltage control system of the magnetoelectric generator with magnetic flux shunting for electric power systems

The object of research in this work is a three-phase magnetoelectric generator with magnetic flux shunting based on industrial induction electric motors. The presence of a magnetic shunt makes it possible to control the voltage of the generator by changing the excitation current in the non-contact electrical winding of the magnetic shunt, which is powered by direct current. Thus, the problem of stabilization of the output voltage of the generator with permanent magnets is solved when the speed of rotation and load change. This paper reports the construction of a three-dimensional field mathematical model of the generator, which allows for electromagnetic calculations of the generator with specified parameters, taking into consideration the influence of final effects, magnetic scattering fields, as well as their radial-axial nature. The results of the calculation of the electromagnetic field are the initial parameters for building a simulation model in the MATLAB-Simulink environment. A simulation model of a magnetoelectric generator with magnetic flux shunting under conditions of changing rotational speed and load has been constructed in the MATLAB-Simulink environment. On the basis of the built models, the performance characteristics of a magnetoelectric generator with magnetic flux shunting were established, which show the limits of control of the output voltage. Adjusting characteristics were determined at zero and rated shunt current for different types of load. The adjusting characteristics of the generator are presented at the rated voltage of the generator for different types of load and with an increase to 150 % of the rated value. The study's results show the high efficiency of the voltage control system of a magnetoelectric generator with a magnetic shunt at different speeds of rotation and load

Gas metal arc welding of metal-polymer-metal sheets

Metal-polymer-metal (MPM) sheets are sandwich panels used for housings of large industrial electric motors and generators, vehicle body panels, flooring, various bulkheads, wheel arching, engine and gearbox shielding, etc. Their main advantage over classic steel panels in form of plates is their acoustic dampening properties. Joining of such plating is challenging because the polymer interlayer evaporates and the resulting fumes may cause the plates to deform. In this paper, GMAW welding was used to join metal-polymer-metal sheets, with a square butt joint, single V butt joint combined in one sheet, as well as welding in one pass per side and in multiple bead segments. C1 (CO2) and M21 (Ar + 18 % CO2) shielding gases were used. Tensile, bending and hardness tests were performed, macro and microstructures were tested and the evaporation, melting and cross-linking distances were recorded. It was shown that contrary to the recent tendency of using M21 shielding gas for GMAW welding, C1 proved to offer superior tensile and bending properties of the joint. From the point of view of simplicity and productivity, a square butt joint proved to be optimal.

Analysis of depolymerization of insulating compositions of electric motor windings based on ultrasonic radiation

This work is a continuation of the fundamental study on implementing an innovative method of repairing electric motors using ultrasound. A study of the method of dismantling windings based on ultrasound has been carried out for the purpose of energy efficiency, environmental friendliness and less time spent on the repair cycle of electric motors in terms of removing the stator winding. The investigated dismantling method is optimal for a number of technical issues in comparison with the existing methods for dismantling electric motor windings. In the work, the main focus is on the material of the winding insulation. Lacquer and compound types of insulation of industrial electric motors, which are the main ones everywhere, have been analyzed. The analysis of the impregnating electrical insulating compositions of the stator windings of electric motors and the influence of ultrasound on them during dismantling of the windings of electric motors at different levels of influence of forcing factors: duration and power of ultrasonic action, concentration and temperature of the working solution. The applied mathematical software systems for calculation and modeling guarantee the reliability and rationality of the results of the experiments obtained during the work. A system of equations has been modeled and models of the effect of useful factors relative to each other have been constructed, the results obtained have been optimized and the optimal parameters of both varnish and compound insulation systems have been identified. The optimal parameters of the investigated types of insulation show encouraging results on many important points: duration, energy consumption, environmental friendliness.

Vibration-based bearing fault diagnosis using relevant multi-domain features and hierarchical stochastics classification

Bearings installed in industrial electric motors, currently are constituted as the main mode of a failure affecting the global energy consumption. Since energy demand from light industry only grows, demand for effective maintenance in electric motors is critical. Proper life management of such assets focuses on the study of the useful life, delivering efficient information about location and severity of different health status, and using vibration signals from bearings with analysis approaches based on characteristics in time, frequency and time-frequency domains. These domains are characterized by its own benefits as well as its shortcomings, and thus most current works focus only on one of these analyses’ domain. This paper studies a possible sub-relevant set of features that favor separability between classes of severity levels to perform training on a concatenation of hierarchical HMM in order to analyze multiple health conditions in bearings, including faults and severities in the following rolling elements: ball, inner race, and outer race. As a result, a substantial improvement is observed in the diagnosis of fault type and severity level present in the bearings and being in concordance with previous studies where just overall process is reported.

A Review of Circular Economy Research for Electric Motors and the Role of Industry 4.0 Technologies

The market for electric motors is experiencing a step-growth due to their adoption across a range of industrial sectors. This increased demand also highlights the importance of end-of-life management of electric motors and a requirement for appropriate strategies for the high value materials embedded in them. This paper aims to offer a holistic view on the circular economy research for electric motors and the role of Industry 4.0 technologies by presenting the state-of-the-art available in literature and comparing it with the industrial perspective. The literature review revealed the absence of a methodology for selecting the best end-of-life scenario for industrial electric motors. Recycling, which is an end-of-product-life strategy, was found to be the key focus area of research. Reuse, which is a better strategy in terms of waste hierarchy, was the least researched area due to lack of information about the condition and availability of returned products. In order to capture the current landscape within the UK for the repair, remanufacture and recycling of electrical machines, a structured survey of UK based companies was conducted. The survey revealed that nearly half of the companies do not undertake any repair strategies for electrical machine components; however, there was an aspiration from the respondents to migrate their companies towards more sustainable activities. The industry survey and the review of existing literature led to the identification of research trends, challenges and recommendations for future research.

Investigation of the effect of ultrasonic radiation on varnished and compounded impregnating compositions with an innovative method of dismantling electric motor windings

For the purposes of energy efficiency, ecology and less time for the cycle of repairing electric motors in the part of the excavation of the stator winding, an innovative method for dismantling ultrasound-based windings has been investigated. From a technical point of view the method has shown to be more optimal in comparison with existing methods of removing the winding. The paper is a continuation of fundamental research on the development of an innovative method of repairing electric motors. It is in this article that the main emphasis is placed on the material from which the insulation of windings is made. Lacquer and compound insulations have been considered being the main types of insulation of industrial electric motors in our country. The analysis of impregnating electrical insulation compositions of motor stator windings has been carried out; the ultrasound effect during the dismantling of motor windings at different levels of influencing factors has been studied, namely duration and power of ultrasonic action, concentration and temperature of the working solution. The validity of the scientific results obtained in the work is confirmed by the correctness of the applied mathematical apparatus and the methods of mathematical modeling, the convergence of the results of numerical modeling and full-scale experiments. A system of equations has been simulated and models of the effect of useful factors relative to each other have been built, the results obtained have been optimized during the experiment and the optimal parameters of both lacquer and compound insulation systems have been identified. The optimal parameters of the types of insulation under study have shown encouraging results on many important points compared to the existing ones: duration, energy consumption, and environmental friendliness. The validity of the conclusions regarding the adequacy of the mathematical models used has been confirmed by the results of experimental studies conducted in the framework of this work of the process of depolymerization of the electric motors' stator windings.

Implementasi Penggunaan Modul Praktek PLC CP1E Pada Pelajaran Produktif Kompetensi Pengontrolan Motor Listrik Pada Program Keahlian Teknik Ketenagalistrikan SMK Negeri 3 Sorong Provinsi Papua Barat

PLC control is basically a computer designed to replace a relay-based system. SMK Negeri 3 Sorong as one of the Vocational High Schools in Sorong-West Papua has an Electricity Engineering Expertise Program that studies PLC mastery competencies, but from observations made by researchers at SMK Negeri 3 Sorong it turns out that it does not have adequate practice modules in the subject of applying PLC to control of industrial electric motors and there are also difficulties for teachers in these schools in providing learning competency in electric motor control techniques, especially in terms of application or practice. The implementation of the module that will be designed and applied is a learning medium that will help the process of practicing skills in electric motor control engineering competencies automatically using the PLC Omron CP1E module. This module is designed to pay attention to several important things as follows: (1). Practice module in accordance with existing competency standards, (2). Easy to use, and (3). Helps the level of understanding of teachers and students in applying it. This practical module is also used to study the working principle parts of the up / down motor control system with the addition of a simulation module of the lift motor work system using a limit switch that detects the presence of the lift box. At the PLC output, a motor power window and lift indicator are used which indicate the lift box is automatically running.

Bearing Health Monitoring Using Relief-F-Based Feature Relevance Analysis and HMM

Nowadays, bearings installed in industrial electric motors are constituted as the primary mode of a failure affecting the global energy consumption. Since industries’ energy demand has a growing tendency, interest for efficient maintenance in electric motors is decisive. Vibration signals from bearings are employed commonly as a non-invasive approach to support fault diagnosis and severity evaluation of rotating machinery. However, vibration-based diagnosis poses a challenge concerning the signal properties, e.g., highly dynamic and non-stationary. Here, we introduce a knowledge-based tool to analyze multiple health conditions in bearings. Our approach includes a stochastic feature selection method, termed Stochastic Feature Selection (SFS), highlighting and interpreting relevant multi-domain attributes (time, frequency, and time–frequency) related to the bearing faults discriminability. In particular, a relief-F-based ranking and a Hidden Markov Model are trained under a windowing scheme to achieve our SFS. Obtained results in a public database demonstrate that our proposal is competitive compared to state-of-the-art algorithms concerning both the number of features selected and the classification accuracy.

OPTIMIZACIJA ELEKTROLUČNOG ZAVARIVANJA TOPLJIVOM ELEKTRODOM U ZAŠTITNOM GASU PRI ZAVARIVANJU MPM SENDVIČ LIMOVA

Pojavom sve strožijih zahteva za smanjenje buke i vibracija, pojavljuju se i novi materijali koji mogu da ispune te zahteve. Jedan od tih materijala jesu metal – polimer – metal (MPM) sendvič paneli korišćeni kao antiakustična barijera, za kućišta indstri-jskih generatora i elektromotora. Zavarivanje ovih panela je zbog prisustva polimernog sloja problematično i može da rezultuje deformacijama, odnosno razdvajanjem čeličnih ploča. U ovom radu, prikazana je optimizacija tehnologije zavarivanja, sa ciljem da se na što ekonomičniji način, izvrši zavarivanje, uz što manje isparavanje polimernog međusloja.

Effect of load current harmonics on vibration of three-phase generator

Almost all today electrical loads are considered non-linear such as switch mode power supply (SMPS) for powering computer and mobile phone or variable speed drive (VSD) for driving home and industrial electric motors. These loads generate ac non-sinusoidal current containing a lot of harmonics as indicated by its high total harmonics distortion (THD) figure. Current harmonics bring negative effects into all electrical power system components, including three-phase generator. This paper provides analysis of load current harmonics effects on vibration of three-phase generator. Three different laboratory experiments have been conducted i.e. three-phase linear resistive loading, non-linear loading with a three-phase ac/dc converter and non-linear loading with three single-phase capacitor filtered ac/dc converters. Results show that the higher load current harmonics content the higher is vibration of the three-phase generator. Non-linear loading with a three-phase ac/dc converter that generate about 24.7% THD gives an increase of 4.3% and 5.5% in average of vertical and horizontal vibrations of the three-phase generator respectively. Further, non-linear loading with three single-phase capacitor filtered ac/dc converters that generate THD as high as 74.9% gives significant increase of 28.1% and 23.6% in average of vertical and horizontal vibrations respectively.

Techno-economic analysis of energy efficiency improvement in electric motor driven systems in Swiss industry

According to its ‘Energy Strategy 2050’ (case ‘new energy policy’) Switzerland aims to reduce its industrial electricity demand by 25% and 35% in 2035 and 2050 respectively compared to 2010. Electric motor driven systems in Swiss industry, which currently account for approximately 69% of the sector’s total electricity demand, are expected to contribute significantly to this strategy. This study assesses the potential of electricity savings for electric motor driven systems in industry and its associated specific costs and presents the results in the form of energy efficiency cost curves. For the short term, the economic potential for electricity savings in Swiss industrial electric motor systems is estimated at approximately 17%. The importance of accounting for additionality by using energy-relevant investment instead of total investment for the cost-benefit analysis in order to avoid underestimation of the economic electricity savings potential is demonstrated. The results of this analysis can serve as basis for formulating more effective policies and may also be applicable to other countries with similarly ambitious targets.

GMAW Welding of MPM Sheets in Active Gas

MPM sheets represent the sanwich panels consisted of two low carbon steel sheets 3 mm thick separated by a visco-elastic inner layer. It is used for dampening the structure borne sound and it replaces the structural sheet metal without taking up a considerable amount of space. The inner layer, however, makes the welding more difficult, since it burns when exposed to relatively high welding temperatures. This may cause distorsion and separation of sheet metal, as well as the loss in sound dampening properties. Therefore, it is of utmost importance that the visco-elastic inner layer remains intact as much as possible, while still maintaining a low cost and a high productivity during welding of MPM sheet housing of large industrial electric motors and generators. In this paper, gas metal arc welding (GMAW) with CO2 active gas was used in an attempt to produce suitable butt welds, welded from both sides. To prevent distorsion and burning of inner layer different butt welds were tested. Different combinations of the following welds were tested: open square weld, combined open square weld on one sheet and single V on the other side, welding in one pass on each side and welding in multiple bead segments on each side. It was found that in all cases, a full penetration was achieved. Furthermore, inner layer thickness near the weld and potential distorsion strongly depend on the welding methodology used.

Diagnostics of Synchronous Motor Based on Analysis of Acoustic Signals with the use of Line Spectral Frequencies and K-nearest Neighbor Classifier

Abstract In industrial processes electrical motors are serviced after a specific number of hours, even if there is a need for service. This led to the development of early fault diagnostic methods. Paper presents early fault diagnostic method of synchronous motor. This method uses acoustic signals generated by synchronous motor. Plan of study of acoustic signal of synchronous motor was proposed. Two conditions of synchronous motor were analyzed. Studies were carried out for methods of data processing: Line Spectral Frequencies and K-Nearest Neighbor classifier with Minkowski distance. Condition monitoring is useful to protect electric motors and mining equipment. In the future, these studies can be used in other electrical devices.

Flexible Automation for the Production of Stators and Rotors of Electric Vehicles

The increasing electrification of the drive train will - sooner or later - lead to significant changes in the value chains for vehicle manufacturers and suppliers, while sales potentials are still uncertain. Due to the currently small number and high diversity of industrial electric motors with higher power and the complex handling of the necessary materials, the processes are based on manual labor content. For the automotive industry high volume production concepts for electric traction motors will be required in the future. Thus, the importance of automated assembly and manufacturing technologies for electric motors moves into focus. In the production of electric motors e.g. the wiring processes of the stators and the magnet assemblies for permanent-magnet synchronous rotors show potential for further process rationalization. This paper presents alternative approaches for the automation of wiring and magnet assembly processes developed at the Institute for Factory Automation and Production Systems (FAPS) at the Friedrich-Alexander-University of Erlangen-Nuremberg.