örvényáramveszteségek

örvényáramveszteségek, also known as eddy current losses, are a type of energy loss that occurs in ferromagnetic materials when subjected to a changing magnetic field. This phenomenon is described by Faraday's law of induction. As the magnetic flux through the material changes, it induces circulating currents within the material itself, much like a transformer. These induced currents, known as eddy currents, flow against the magnetic field and dissipate energy in the form of heat due to the electrical resistance of the material.

The magnitude of eddy current losses is proportional to the square of the frequency of the changing magnetic field, the square of the magnetic flux density, and the thickness of the conductive material. Conversely, it is inversely proportional to the material's resistivity. This means that higher frequencies, stronger magnetic fields, and thicker conductive materials will result in greater energy losses.

To minimize eddy current losses in applications such as transformers, motors, and generators, the conductive core is typically constructed from thin laminations of ferromagnetic material. These laminations are insulated from each other by a thin layer of varnish or oxide. This insulation increases the overall resistance of the core, thereby significantly reducing the magnitude of the induced eddy currents and consequently the associated power losses. Laminated cores are a fundamental design element in many electrical machines to improve efficiency.