Hysteresisveszteséggel

Hysteresisveszteséggel, often translated as hysteresis loss, refers to energy dissipation that occurs when a magnetic material is subjected to a cycle of magnetization and demagnetization. This phenomenon is a consequence of the irreversible changes in the magnetic domain structure within the material as the external magnetic field is varied.

When a ferromagnetic material is magnetized, its magnetic domains align with the applied field. As the field is increased, more domains align, and the material becomes more strongly magnetized. However, the alignment is not perfectly linear. When the external field is reduced, the domains do not fully return to their original disordered state. Some residual magnetism, known as remanence, remains. To demagnetize the material completely, a reverse magnetic field, called the coercive field, must be applied.

The energy loss associated with hysteresis is represented by the area enclosed within the hysteresis loop on a B-H graph, where B is the magnetic flux density and H is the magnetic field strength. This energy is converted into heat within the material due to friction-like processes as domain walls move and reorient.

Hysteresis loss is an important consideration in the design of electrical devices that utilize magnetic materials, such as transformers, motors, and magnetic storage media. Minimizing hysteresis loss is crucial for improving the efficiency of these devices. Materials with narrow hysteresis loops, known as soft magnetic materials, are preferred for applications where frequent magnetization cycles occur, while materials with wide hysteresis loops, called hard magnetic materials, are used for permanent magnets where high remanence and coercivity are desired.