Materials In Electrical Machines Research Articles

Formation of cube-on-face texture {0 0 1}〈uv0〉 in a high saturation soft magnetic iron-cobalt-vanadium alloy by controlled phase-transformation γ → α

In this investigation, the soft magnetic properties of a high saturation iron-cobalt-vanadium alloy with 17 wt% Co and 1.5 wt% V have been greatly enhanced by a special heat treatment in the γ-region, which effectively leads to the formation of a magnetically favorable strong cube-on-face texture during cooling. Based on EBSD analyses, a high degree of cube-on-face texture {001}〈uv0〉 of up to 80 % was obtained. The underlying mechanism is presumed to be a preferred surface nucleation of {001}-grains during cooling through the two-phase-region α + γ. The annealing of all samples was performed in ceramic powder. Therefore, mechanical stress is not considered the primary cause for this preferred nucleation, which should simplify the upscaling to an industrial process. As the 〈100〉 direction is the magnetic easy axis in this material system, this preferred crystal orientation goes along with very good soft magnetic properties such as a high maximum permeability µmax of 16,000, an increased induction B(160 A/cm) of 2.14 T and a reduced coercivity Hc of about 30 A/m. The core loss is reduced for frequencies up to 1 kHz. This favorable combination of properties, along with the reduced Co content, opens up new possibilities for the use of this material in electrical machines with both a high efficiency and a high power density.

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.

Characterization of Rotational Magnetic Properties of Amorphous Metal Materials for Advanced Electrical Machine Design and Analysis

Amorphous metal (AM), specifically amorphous ferromagnetic metal, is considered as a satisfactory magnetic material for exploring electromagnetic devices with high-efficiency and high-power density, such as electrical machines and transformers, benefits from its various advantages, such as reasonably low power loss and very high permeability in medium to high frequency. However, the characteristics of these materials have not been investigated comprehensively, which limits its application prospects to good-performance electrical machines that have the magnetic flux density with generally rotational and non-sinusoidal features. The appropriate characterization of AMs under different magnetizations is among the fundamentals for utilizing these materials in electrical machines. This paper aims to extensively overview AM property measurement techniques in the presence of various magnetization patterns, particularly rotational magnetizations, and AM property modeling methods for advanced electrical machine design and analysis. Possible future research tasks are also discussed for further improving AM applications.

Review of the Application of Composite Materials in Electrical Machines

This paper describes typical composite materials that are already used or can be used in the components of electrical machines. In the presented review of composite materials, their main advantages and limitations are identified. Specific examples of the use of composite materials in electrical machines are given. This article also studies the feasibility and the fundamental possibility of creating an electrical machine for microturbines entirely composed of composite materials. For this purpose, electromagnetic and thermal analyses using finite element methods have been performed. According to the results of these analyses, a comparison of the characteristics of an electrical machine is made consisting of traditional materials and electrical machines partly or fully consisting of composite materials. As a result, proposals are formed on the prospects for the use of composite materials in electrical machines. The main contribution of this article in the field of design and creation of electrical machines is the synthesis of data on composite materials used in electrical machines, as well as the demonstration of the prospects of an electrical machine entirely composed of composite materials.

Role of advanced materials in electrical machines

There has been a revived and growing role for electrical machines and drives across a wide range of applications. Such applications include, hybrid/electrical traction applications, aerospace applications, and renewable energy. All these applications present different set of requirements and challenges. The common trend is that there is a need for higher-performance electrical machines in terms of higher power/torque density, and higher efficiency while keeping cost under control. There has been a lot of work done around coming up with novel machine topologies, optimizing more conventional topologies as well as improved thermal management schemes. Like many other areas of engineering/research, advanced materials can play a key role in opening up the design space for electrical machines leading to a step improvement in their performance. This paper will present an overview of some of the key advanced materials that are either recently developed or are currently under development and their potential impact on electrical machines.

Multiphysics Analysis of a Stator Construction Method in Yokeless and Segmented Armature Axial Flux PM Machines

Increasing performance requirements for electrical machines such as energy efficiency and torque density require a multiphysics design approach. In these designs, many machine parts very often combine multiple functions, such as electromagnetic, thermal, and mechanical, to keep the design compact and reduce the overall weight, or introduce nonconventional materials in electrical machines. In this paper, epoxy potting techniques are used to keep the different stator parts of a yokeless and segmented armature axial flux PM machine together, and it focuses mainly on the multiphysics aspects of the epoxy resins as well as on their implications on the overall stator design. In this multiphysics design approach, the effect of specific epoxy resin parameters such as maximum service temperature, thermal conductivity, Brookfield viscosity, tensile strength, and coefficient of thermal expansion, on the electromagnetic, thermal and mechanical behavior of the stator are examined. Epoxy resin parameters are evaluated in detailed experiments on small test samples, and finally, measurements on a full prototype 4 kW, 2500 rpm stator are performed.

Use of magnetic materials in electrical machines in vehicles

The most common types of permanent magnets are considered. A study of their properties, positive and negative properties is conducted.

Applications of soft magnetic composite materials in electrical machines

Soft magnetic composite (SMC) materials and their uses in electrical machines have undergone significant development in the past decade. The major advantages of the materials include isotropic magnetic and thermal properties, very low eddy current loss and relatively low total core loss at medium and higher frequencies, and low cost fabrication with good tolerance and surface finish using the well developed powder metallurgical techniques that require no further machining. It is even anticipated that the application of SMC may lead to a revolutionary development in the electrical machine manufacturing industry. This paper reviews the application of SMC in electrical machines. Both successful experiences and existing difficulties are discussed, and possible further work required for the commercial success of SMC machines is proposed.

Design and construction of a single phase claw pole permanent magnet motor using composite magnetic material

To investigate the application of composite magnetic materials in electrical machines, a small single phase claw pole permanent magnet motor using soft material as the stator core has been designed and constructed. Based on the three-dimensional magnetic field analysis, the induced stator emf, cogging torque, and the steady state motor performance when operated as a synchronous motor are predicted.

Power loss in electrical steel under elliptically rotating flux conditions

The power loss of electrical steel sheet given in the data sheets of the steel manufacturers is related to linearly alternating flux conditions, measured with an Epstein frame or a single sheet tester, respectively. In the application of the material in electrical machines, we find large areas with rotational flux conditions, i.e., in the T-joint region of three-phase power transformers or above the stator teeth of three-phase motors and generators. The most general description of the magnetization process in this case is an elliptically rotating flux. The paper outlines the magnetic behavior of steel sheet under these flux conditions, and finally defines a simple method to predict the total power loss under elliptically rotating flux from data measured under linearly alternating and circularly rotating flux conditions only.