Simple calculation of eddy currents in a long passive conductor

2019 ◽  
Vol 61 (2) ◽  
pp. 201-224 ◽  
Author(s):  
Oldřich Coufal ◽  
Branislav Bátora ◽  
Lukáš Radil ◽  
Petr Toman
Keyword(s):  
Eddy Currents ◽  
Simple Calculation ◽  
Long Passive

Determination of eddy current losses and hysteresis losses in magnetic circuits of electrical machines

2020 ◽  
pp. 54-58
Author(s):  
S. M. Plotnikov
Keyword(s):  
Eddy Current ◽  
Magnetization Reversal ◽  
Eddy Currents ◽  
Technical Problem ◽  
Electrical Machines ◽  
Eddy Current Losses ◽  
Hysteresis Losses ◽  
Magnetic Circuits ◽  
Core Losses ◽  
Reversal Frequency

The division of the total core losses in the electrical steel of the magnetic circuit into two components – losses dueto hysteresis and eddy currents – is a serious technical problem, the solution of which will effectively design and construct electrical machines with magnetic circuits having low magnetic losses. In this regard, an important parameter is the exponent α, with which the frequency of magnetization reversal is included in the total losses in steel. Theoretically, this indicator can take values from 1 to 2. Most authors take α equal to 1.3, which corresponds to the special case when the eddy current losses are three times higher than the hysteresis losses. In fact, for modern electrical steels, the opposite is true. To refine the index α, an attempt was made to separate the total core losses on the basis that the hysteresis component is proportional to the first degree of the magnetization reversal frequency, and the eddy current component is proportional to the second degree. In the article, the calculation formulas of these components are obtained, containing the values of the total losses measured in idling experiments at two different frequencies, and the ratio of these frequencies. It is shown that the rational frequency ratio is within 1.2. Presented the graphs and expressions to determine the exponent α depending on the measured no-load losses and the frequency of magnetization reversal.

A Simple Calculation Method of Flashover Characteristics for Long Air Gaps under Various Discharge Conditions

1993 ◽  
Vol 113 (3) ◽  
pp. 252-258
Author(s):  
Kiyoto Nishijima ◽  
Itaru Tsuneyasu ◽  
Hiraku Nakahodo ◽  
Masaharu Minakami
Keyword(s):  
Calculation Method ◽  
Simple Calculation ◽  
Air Gaps

Hidden Crack Detection with GMR Sensing of Magnetic Fields from Eddy Currents

2007 ◽  
Author(s):  
Ray T. Ko ◽  
Shamachary Sathish ◽  
Jeremy S. Knopp ◽  
Mark P. Blodgett
Keyword(s):  
Magnetic Fields ◽  
Crack Detection ◽  
Eddy Currents

scholarly journals Modification of the Water Quality Index (WQI) Process for Simple Calculation Using the Multi-Criteria Decision-Making (MCDM) Method: A Review

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 905
Author(s):  
Naseem Akhtar ◽  
Muhammad Izzuddin Syakir Ishak ◽  
Mardiana Idayu Ahmad ◽  
Khalid Umar ◽  
Mohamad Shaiful Md Yusuff ◽  
...  
Keyword(s):  
Water Quality ◽  
Decision Making ◽  
Water Quality Index ◽  
Quality Index ◽  
Water Quality Assessment ◽  
Simple Calculation ◽  
Great Accuracy ◽  
Parameter Selection ◽  
Human Consumption ◽  
Multi Criteria Decision Making

Human activities continue to affect our water quality; it remains a major problem worldwide (particularly concerning freshwater and human consumption). A critical water quality index (WQI) method has been used to determine the overall water quality status of surface water and groundwater systems globally since the 1960s. WQI follows four steps: parameter selection, sub-indices, establishing weights, and final index aggregation, which are addressed in this review. However, the WQI method is a prolonged process and applied to specific water quality parameters, i.e., water consumption (particular area and time) and other purposes. Therefore, this review discusses the WQI method in simple steps, for water quality assessment, based on two multi-criteria decision-making (MCDM) methods: (1) analytical hierarchical process (AHP); and (2) measuring attractiveness by a categorically based evaluation technique (MACBETH). MCDM methods can facilitate easy calculations, with less effort and great accuracy. Moreover, the uncertainty and eclipsing problems are also discussed—a challenge at every step of WQI development, particularly for parameter selection and establishing weights. This review will help provide water management authorities with useful knowledge pertaining to water usage or modification of existing indicators globally, and contribute to future WQI planning and studies for drinking, irrigation, domestic, and industrial purposes.

scholarly journals Effect of the Temperature on the Magnetic and Energetic Properties of Soft Magnetic Composite Materials

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4400
Author(s):  
Luca Ferraris ◽  
Fausto Franchini ◽  
Emir Pošković ◽  
Marco Actis Grande ◽  
Róbert Bidulský
Keyword(s):  
Magnetic Materials ◽  
Eddy Currents ◽  
Electrical Machines ◽  
Soft Magnetic Materials ◽  
Magnetic Composite ◽  
Soft Magnetic ◽  
Soft Magnetic Composite ◽  
Magnetic Performance ◽  
Magnetic Circuits ◽  
Energetic Characterization

In recent years, innovative magnetic materials have been introduced in the field of electrical machines. In the ambit of soft magnetic materials, laminated steels guarantee good robustness and high magnetic performance but, in some high-frequency applications, can be replaced by Soft Magnetic Composite (SMC) materials. SMC materials allow us to reduce the eddy currents and to design innovative 3D magnetic circuits. In general, SMCs are characterized at room temperature, but as electrical machines operate at high temperature (around 100 °C), an investigation analysis of the temperature effect has been carried out on these materials; in particular, three SMC samples with different binder percentages and process parameters have been considered for magnetic and energetic characterization.

Porosity Quatification of Cast Aluminium Alloys on Machined Surfaces Using Metallography and Eddy-Currents

2015 ◽  
Vol 647 ◽  
pp. 188-194
Author(s):  
Břetislav Skrbek
Keyword(s):  
Surface Treatment ◽  
Aluminium Alloys ◽  
Eddy Currents ◽  
Initiation Site ◽  
Cast Aluminium ◽  
Strength And Ductility ◽  
Machined Surfaces

The porosity is unwanted phenomenon mostly that is tried to eliminate. The pores are initiation site of fatigue fractions usually, they worse strength and ductility of materials, quality of machined surfaces and their following surface treatment.

Sign in / Sign up

Export Citation Format

Share Document