Design and Application of Electrical Machines

Design and Application of Electrical Machines is a Special Issue of Energies. In this Special Issue, authors from various research centers present the results of their scientific research on electrical machines. In eighteen papers, they presented simulation studies, design works, and experimental tests on built prototypes.

Electroresistive method for monitoring the technical condition, quality, reliability and safety the supports of rolling of electrical machines

The necessity of monitoring the technical condition of the rolling supports of electric machines has been substantiated. It is proposed to use the electrical resistance of the bearing as an indicator of the technical condition the rolling support. The results of mathematical modeling of electrical resistance in the form of a function of resistance from factors of the internal environment of the bearing and modes of its assembly and operation in a rolling bearing are presented. An electroresistive method for monitoring the technical state the rolling support is proposed, which differs from the known methods by original algorithms for collecting information about the state of bearing parts, experimental studies have been carried out to confirm the efficiency of this method.

Iron Loss Quantification in the Aim of the Estimation of Eddy Currents in Clamping Devices

In high power electrical machines, the leakage magnetic flux due to end windings induces eddy currents in clamping devices. However, it is quite difficult to quantify these losses. In order to study the effect of different clamping materials and the impact of the magnetization direction, an experimental mock-up composed of a stator and a clamping plate has been developed. An axial coil generates a circumferential magnetic flux in the stator core at different frequencies. Eddy current losses in the clamping plates are deduced from a power balance by subtracting Joule losses and iron losses from the total measured losses. Iron losses are deduced from 3D FE calculations while the impact of the frequency on B(H) curve is taken into account. Losses in the clamping device are then analyzed depending on experimental parameters.

LABORATORY STUDIES OF PROPERTIES OF SOFT MAGNETIC POWDER COMPOSITE MATERIALS

Изучение эффективности использования электротехнических материалов является актуальной проблемой в области изготовления электрических машин. Одним из важнейших аспектов изготовления электрических машин является проектирование магнитной системы машины. В качестве магнитной системы используют магнитопроводы из различных магнитомягких материалов. Эти материалы отличаются магнитной проницаемостью и удельными магнитными потерями. Данные параметры материалов влияют на нагрев, размер, стоимость и эффективность электрической машины. В целях экономии экспериментальная оценка параметров магнитомягких материалов производится на заготовках различных форм и размеров, на специальных измерительных стендах, согласно международным энергетическим стандартам. В данной статье предлагается экспериментальная установка для лабораторных исследований магнитных свойств магнитомягких материалов, методом кольцевых заготовок, в соответствие со стандартом МЭК-60404-6. В составе установки используется только стандартное недорогое оборудование. Необходимый коэффициент формы магнитной индукциидостигается последовательной коррекциейнапряжения вторичной обмотки с помощью цифрового регулятора. Подход к программной реализации алгоритма последовательной коррекции напряжения вторичной обмотки изложен в статье. С помощью предлагаемой установки проведено исследование свойств образца из магнитомягкого композиционного порошкового материала Somaloy 700-3p (800 MPa) и сравнение результатов с каталожными данными производителя. По итогам работы выявлено, что с помощью предлагаемойустановки могут производитьсяизмерения свойств магнитомягких материалов, в соответствие со стандартом МЭК-60404-6 с необходимой точностью. Предлагаемая установка может быть использована как в качестве учебного стенда, так и в качестве измерительной установки для идентификации свойств магнитомягких материалов при проектировании электрических машин. The study of the efficiency of using electrical materials is of great interest in the field of manufacturing electrical machines. One of the most important aspects of the manufacture of electrical machines is the design of the magnetic cores of the machine. Magnetic cores made of various magnetically soft materials are used as a magnetic system. These materials differ in magnetic permeability and specific magnetic losses. These material parameters affect the heating, size, cost and efficiency of electric machines. In order to reduce expenses, the experimental evaluation of the parameters of soft magnetic materials is carried out on samples of various shapes and sizes, on special experimental setups, in accordance with international electrotechnical standards. This article proposes an experimental setup for laboratory studies of the magnetic properties of soft magnetic materials by the method of ring specimens, in accordance with the IEC-60404-6 standard. The setup uses only standard inexpensive equipment. The required shape factor of the magnetic flux density is achieved by sequential correction of the secondary winding voltage using a digital regulator. The approach to the software implementation of the algorithm for sequential correction of the secondary winding voltage is described in the article. The proposed experimental setup was used to study the properties of a sample made of a soft magnetic composite powder material Somaloy 700-3p (800 MPa) and compare the results with the manufacturer's catalog data. Based on the results of the work, it was revealed that the proposed setup can be used to measure the properties of soft magnetic materials in accordance with the IEC-60404-6 standard with the required accuracy. The proposed experimental setup can be used both as a training stand and as a measuring installation for identifying the properties of soft magnetic materials in the design of electrical machines.

2D electrostatic modeling of twisted pairs

Purpose This paper aims to model a three-dimensional twisted geometry of a twisted pair studied in an electrostatic approximation using only two-dimensional (2D) finite elements. Design/methodology/approach The proposed method is based on the reformulation of the weak formulation of the electrostatics problem to deal with twisted geometries only in 2D. Findings The method is based on a change of coordinates and enables a faster computational time as well as a high accuracy. Originality/value The effectiveness of the adopted approach is demonstrated by studying different configurations related to the IEC 60851-5 standard defined for the measurement of the electrical properties of the insulation of the winding wires used in electrical machines.