Production Of Electrical Machines Research Articles

Investigation and comparison of permanent magnet rotors produced by different additive manufacturing methods

The advancements in technology have led to a growing interest in additive manufacturing owing to its numerous benefits such as increased degree of freedom, high flexibility, and material conservation. It has gained particular attention in the production of electrical machines and their active components such as windings, electrical insulation, magnetic core packs, and permanent magnets. This paper investigates the use of two methods, namely fused deposition modeling and cold spray, in the production of hard magnetic components for rotors with surface-mounted magnets. A comparative study was conducted through a combination of finite element simulations and experimental tests.

A Review of Additive Manufacturing of Soft Magnetic Materials in Electrical Machines

This paper presents a review of the main advantages and challenges of Additive Manufacturing (AM) applied in the production of soft magnetic components for electrical machines. Firstly, a general introduction about additive manufacturing is made, considering all of its possibilities of application, then the authors focused on the electrical machine application field, in particular the AM of soft ferromagnetic materials. The soft ferromagnetic materials are fundamental for the production of electrical machines, and currently, there are more and more requests for designed ad hoc geometries, which can be difficult to produce with conventional manufacturing technologies. With this purpose, AM can be used to produce the desired geometries.

ПОВЫШЕНИЕ ЭНЕРГОЭФФЕКТИВНОСТИ АСИНХРОННОЙ ЭЛЕКТРИЧЕСКОЙ МАШИНЫ ЗА СЧЕТ ОПТИМИЗАЦИИ УДЕЛЬНЫХ ПОКАЗАТЕЛЕЙ

The role of the electric motor in industry is clearly high. However, speaking about complex mechanisms, the use of elec-tromechanical converters of a specific series is impractical due to low energy efficiency. In the technical literature, electric drives used the term “registered” electric machines, i.e. machines manufactured for a specific technological mechanism, for example, the nominal motor of the main drive of the 5000 MMK mill (the installed power of one motor is 12 MW). The most common type is asynchronous due to its obvious advantages. The development of semiconductor technology makes it possible to expand the scope of regulation and control of IM, which in turn changes the vector in the production of elec-trical machines. The main idea is to create the most energy-efficient electric motor by changing the geometry of the stator and rotor, voltage shape, number of phases, number of poles, etc. Thus, to implement the existing idea, it is necessary to study the region of magnetic field formation by using parametric optimization and achieving the maximum root-mean-square torque.

Process design and evaluation for the automation of interphase insulation for distributed windings

In the production of electrical machines based on the pull-in technology, the stator, with a share of 35% of the total costs, is the most expensive component in the electric motor and offers a variety of automation possibilities of the process. The insertion of the phase insulation paper into the stator winding head is mostly done within manual assembly stations. This process step offers automation potential for the production of a process-safe phase insulation. The aim is to develop and qualify an automated application method. Therefore, the process is redesigned by the idea of a robot-supported application of the phase insulation with a spray system. For feasibility studies, a robot-supported spray insulation system is designed, built and subsequently integrated into a robot cell. Using several test setups, different process tests are carried out to check the application possibilities of sprayable insulation materials as phase insulation in the stator winding head. In particular, the effects of the various process parameters on the indentation strength of the new insulation materials are being investigated using laboratory tests.

The place and role of corporations in domestic machine building

The main trends in the development of machine-building enterprises in Ukraine are studied. The research proves that large and medium-sized machine-building enterprises sell more products, and the level of profitability of their activities is higher than that of small enterprises. These trends are due, in particular, to the fact that large and medium-sized machine-building enterprises could provide greater funding for the production and development of technical and technological processes, the creation of research units and diversification of markets through international trade and more. A decrease in investment in the development of domestic machine-building industries and a decrease in the share of machine building in investment financing of the industrial sector of the economy are revealed. The paper specifies that in recent years, international corporations, which have established their subsidiaries and production units in Ukraine, have started to play a significant role in the structure of machine-building industries. The share of TNCs in machine-building industries is determined. In particular, the paper shows that in 2020, about 18 subsidiaries of well-known world manufacturers of machine-building products were active, producing 10.45% of sold machine-building products in Ukraine. Such companies involved 10.32% of mechanical engineering workers in general, and the wage bill was 12.45%. The production specialization of machine-building TNCs is outlined. These are mostly intermediate manufacturers engaged in the manufacture of individual components for leading automotive companies. The research emphasizes that the vast majority of machine-building TNCs in Ukraine operate on tolling schemes. Foreign companies are the consumers of TNCs' final products. Accordingly, the share of such products in the Ukrainian export of mechanical engineering is also quite high. This primarily applies to the production of electrical machines (subgroup 85). The expediency of the development of domestic industries to strengthen their competitive position in domestic and foreign markets is emphasized.

Співробітництво з AEG у 1925–1928 рр. як перша форма науково-технічних запозичень в електромашинобудуванні Української СРР

Scientific-technical borrowings are one of those types of scientific support for the work of industrial sectors, whose role in the conditions of exiting the crisis to acquiring the particular importance. Since the mid-1920s, they have become the main how of scientific support for the organization of the development of Ukrainian electric machine-building industry in the context of large-scale electrification of the country. That was due to the need for a quick withdrawal of this industry from the previous crisis in the absence in the Ukrainian SSR of its own scientific support system for the electric machine engineering. The first form of scientific-technical borrowings for the republican segment of the Soviet Union profile industry was the agreement between the State Electrotechnical Trust and the German electrotechnical company Allgemeine Elektricitäts Gesellschaft on scientific-technical cooperation. The main objective of this act was to achieve at the lowest possible financial cost the fastest possible increase in productivity of the Kharkiv Electromechanical Plant. To do this, it was supposed using the American technologies for the production of electrical machines but implemented them on German technological equipment. Allgemeine Elektricitäts Gesellschaft was the company that already made such it at the beginning of the twentieth century using the technologies of the General Electric Company. Moreover, in the pre-Soviet period, it made an attempt to hold a similar act at the Kharkiv Electromechanical Plant, which it owned in this time; however it ended in failure due to the revolutionary upheavals that began in Ukraine. Thus, the agreement concluded with the German company was a continuation of the same actions, what itself had begun, but, already in new historical realities. That is, the Allgemeine Elektricitäts Gesellschaft actions were copied by the Soviet government, however, adapted to the Soviet way of organizing industrial production. Despite the fundamental difference between the latter and the working conditions of the Allgemeine Elektricitäts Gesellschaft in Germany, the concentration of the parties precisely on the scientific and technical component of the project made it possible to achieve the expected result in full. However, at the same time, Ukrainian electric machine builders focused specifically on the speed of duplication of scientific-technical knowledge missed the opportunity to study the methodology for obtaining them. This became the reason that these scientific-technical borrowings did not become the proper basis for the formation of the scientific component of the scientific-technical potential of the domestic electric machine-building industry.

Additive Manufacturing and Testing of a Soft Magnetic Rotor for a Switched Reluctance Motor

Additive manufacturing is acknowledged as a key enabling technology, although its adoption is still constrained to niche applications. A promising area for this technology is the production of electrical machines (EMs) and/or their main components (e.g. magnetic cores, windings, heat exchangers, etc.) due to the potential of creating lightweight, highly efficient rotating motors, suitable for applications requiring a low moment of inertia. This work investigates the readiness of metal additive manufacturing, specifically Laser Powder Bed Fusion (LPBF), applied to the field of EMs to bridge the gaps of how to use this technological approach in this field. A soft magnetic material featuring high silicon content (Fe-5.0%w.t.Si) has been developed for LPBF and a rotor has been 3D-printed for a switched reluctance machine. The printed rotor was assembled into a conventionally laminated stator and the performance of the whole machine was evaluated. Its performance was compared against an identical machine equipped with a laminated rotor of the same dimensions made of conventional non-oriented silicon steel. A comparative study was carried out through both finite element simulations and experimental tests. The efficiency of the two machines was assessed together with the principal electrical and mechanical quantities under several operating conditions.

Effect of copper content on the properties of graphite-copper composites formed using the plasma spray process

Graphite‑copper composite coatings are often used for the production of electrical machines because they are characterized by stable electrical and mechanical properties. The plasma spraying method was used to form such coatings in this work, as we aimed to evaluate the influence of copper content in the initial powders on the properties of graphite‑copper composite coatings. The graphite‑copper coatings were deposited on stainless steel and quartz glass substrates, as the copper content of the initial powder ranged from 2 to 60%. As shown by SEM studies, at small amounts of copper (up to 10%) in the initial powder the micro-derivatives of the spherical form are formed on the coatings. Meanwhile, XRD analysis have shown that mechanical stresses due to different thermal expansion coefficients between the coating and the substrate are characteristic for graphite‑copper coatings. The measurements of electrical conductivity shown that the maximum electrical conductivity (of 10 S) is obtained when the copper content in the initial powder reaches 20%. Despite the increase of the copper content in the initial powder above 20% the electrical conductivity of the coatings remain constant. The microhardness studies have shown that with the increase of copper content in initial powder from 2 to 60%, the microhardness of graphite‑copper composite coatings is reduced by about 2 times, while the plasticity increase from 11 to 19% is observed.

A Review of Design Optimization Methods for Electrical Machines

Electrical machines are the hearts of many appliances, industrial equipment and systems. In the context of global sustainability, they must fulfill various requirements, not only physically and technologically but also environmentally. Therefore, their design optimization process becomes more and more complex as more engineering disciplines/domains and constraints are involved, such as electromagnetics, structural mechanics and heat transfer. This paper aims to present a review of the design optimization methods for electrical machines, including design analysis methods and models, optimization models, algorithms and methods/strategies. Several efficient optimization methods/strategies are highlighted with comments, including surrogate-model based and multi-level optimization methods. In addition, two promising and challenging topics in both academic and industrial communities are discussed, and two novel optimization methods are introduced for advanced design optimization of electrical machines. First, a system-level design optimization method is introduced for the development of advanced electric drive systems. Second, a robust design optimization method based on the design for six-sigma technique is introduced for high-quality manufacturing of electrical machines in production. Meanwhile, a proposal is presented for the development of a robust design optimization service based on industrial big data and cloud computing services. Finally, five future directions are proposed, including smart design optimization method for future intelligent design and production of electrical machines.

A scalable life cycle inventory of an electrical automotive traction machine\u2014Part II: manufacturing processes

PurposeA scalable life cycle inventory (LCI) model of a permanent magnet electrical machine, containing both design and production data, has been established. The purpose is to contribute with new and easy to use data for life cycle assessment (LCA) of electric vehicles by providing a scalable mass estimation and manufacturing inventory for a typical electrical automotive traction machine. The aim of this article (part II of two publications) is to present the manufacturing data with associated collection procedures, from material constituents to complete motor. Another objective is to explain the gate-to-gate system boundaries and the principles for linking the LCI model upstream, to database data, in order to create a full cradle-to-gate dataset.MethodsData for design and production of electrical machines has been compiled from books, scientific papers, benchmarking literature, expert interviews, various specifications, factory records, and a factory site visit. For the manufacturing part, new primary data was collected directly from industry, with a motor factory and a steel mill in Sweden as main contributors, and from technical literature. Other LCA publications were used, if presented in sufficient detail to be disaggregated and revised, to match the gaps of the model. The data represents the current level of technology and targets high-volume manufacturing to the largest extent possible. Also, flows crossing the system boundary have a recommended link to Ecoinvent data, or a request for an attentive selection of input data, depending on the user’s object of study. A distinction was made between the regular and an extended system boundary, wherein the processing of some smaller subparts was accounted for through proposals of ready-made Ecoinvent activities for production efforts.Results and discussionAn extensive new dataset representing electrical machine manufacturing is presented, and, together with the estimation of motor mass and configuration of article part I, it forms a comprehensive scalable LCI model of a typical automotive electric traction motor. New production data includes a complete motor factory, electrical steel production, and the fabrication of a neodymium-dysprosium-iron-boron (Nd(Dy)FeB) magnet. In addition, smaller, new datasets cover the composition of silicon steel, the making of electrolytic iron, enameling of copper wire, and die casting of aluminum.ConclusionsSuccessful data generation required “data building” from multiple sources and access to expert support. Transparent, well-explained, and disaggregated data records were found to be crucial for LCA data validation and usefulness.

A scalable life cycle inventory of an electrical automotive traction machine\u2014Part I: design and composition

PurposeA scalable life cycle inventory (LCI) model of a permanent magnet electrical machine, containing both design and production data, has been established. The purpose is to contribute with new and easy-to-use data for LCA of electric vehicles by providing a scalable mass estimation and manufacturing inventory for a typical electrical automotive traction machine. The aim of this article (part I of two publications) is to present the machine design, the model structure, and an evaluation of the models’ mass estimations.MethodsData for design and production of electrical machines has been compiled from books, scientific papers, benchmarking literature, expert interviews, various specifications, factory records, and a factory site visit. For the design part, one small and one large reference machine were constructed in a software tool, which linked the machines’ maximum ability to deliver torque to the mass of its electromagnetically active parts. Additional data for remaining parts was then gathered separately to make the design complete. The two datasets were combined into one model, which calculates the mass of all motor subparts from an input of maximum power and torque. The range of the model is 20–200 kW and 48–477 Nm. The validity of the model was evaluated through comparison with seven permanent magnet electrical traction machines from established brands.Results and discussionThe LCI model was successfully implemented to calculate the mass content of 20 different materials in the motor. The models’ mass estimations deviate up to 21% from the examples of real motors, which still falls within expectations for a good result, considering a noticeable variability in design, even for the same machine type and similar requirements. The model results form a rough and reasonable median in comparison to the pattern created by all data points. Also, the reference motors were assessed for performance, showing that the electromagnetic efficiency reaches 96–97%.ConclusionsThe LCI model relies on thorough design data collection and fundamental electromagnetic theory. The selected design has a high efficiency, and the motor is suitable for electric propulsion of vehicles. Furthermore, the LCI model generates representative mass estimations when compared with recently published data for electrical traction machines. Hence, for permanent magnet-type machines, the LCI model may be used as a generic component estimation for LCA of electric vehicles, when specific data is lacking.

Laser remote cutting and surface treatment in manufacturing electrical machines—High productivity, flexibility, and perfect magnetic performance

From industrial electrical machine production, it is well known that processing of nonoriented electrical steels causes changes in the lattice and microstructure that also affect the magnetic structure. While applying these manufacturing techniques (punching or laser fusion cutting), mechanical and thermal stresses are induced due to elastic and plastic deformation or temperature gradients within the material. For more than 15 years, fusion cutting with CO2-lasers enabled a flexible and wear-free production but mostly for prototypes and small batches. Ten years ago, the development of diffraction limited solid-state lasers started and thus enabled laser remote cutting (LRC). Nowadays, industry demands sheet thicknesses between 0.35 and 0.5 mm due to the fact of eddy current loss reduction. Concerning this context, best choice is LRC. Within this work, latest results are presented in terms of resulting cutting speed, cutting edge quality, and magnetic properties. Cutting speed of LRC beats laser fusion cutting keeping the high rate of flexibility. The magnetic material properties of laser remote cut laminates are identical or even better to conventional punched parts. Therefore, the manufacturer has been given the possibility to tweak his process toward perfect magnetic behavior or high output volume. All in all, it will be possible to produce high efficient electrical machines regarding the application demands of the costumer.