Search results
Results from the WOW.Com Content Network
Copper loss is the term often given to heat produced by electrical currents in the conductors of transformer windings, or other electrical devices. Copper losses are an undesirable transfer of energy , as are core losses , which result from induced currents in adjacent components.
The methods described included all the heat generation mechanisms from a power cable (conductor loss, dielectric loss and shield loss). [ 2 ] From the basic principles that electric current leads to thermal heating and thermal power transfer to the ambient environment requires some temperature difference, it follows that the current leads to a ...
A different form of short-circuit testing is done to assess the mechanical strength of the transformer windings, and their ability to withstand the high forces produced if an energized transformer experiences a short-circuit fault. Currents during such events can be several times the normal rated current.
where is the time average power loss per unit volume in mW per cubic centimeter, is frequency in kilohertz, and is the peak magnetic flux density; , , and , called the Steinmetz coefficients, are material parameters generally found empirically from the material's B-H hysteresis curve by curve fitting. In typical magnetic materials, the ...
However, in applications where heating is an unwanted by-product of current use (e.g., load losses in electrical transformers) the diversion of energy is often referred to as resistive loss. The use of high voltages in electric power transmission systems is specifically designed to reduce such losses in cabling by operating with commensurately ...
In electrical engineering, dielectric loss quantifies a dielectric material's inherent dissipation of electromagnetic energy (e.g. heat). [1] It can be parameterized in terms of either the loss angle δ or the corresponding loss tangent tan( δ ) .
The overall heat transfer coefficient is a measure of the overall ability of a series of conductive and convective barriers to transfer heat. It is commonly applied to the calculation of heat transfer in heat exchangers, but can be applied equally well to other problems.
The number of transfer units (NTU) method is used to calculate the rate of heat transfer in heat exchangers (especially parallel flow, counter current, and cross-flow exchangers) when there is insufficient information to calculate the log mean temperature difference (LMTD). Alternatively, this method is useful for determining the expected heat ...