Magnettihäviöt

Magnettihäviöt, often translated as magnetic losses, refers to the energy dissipated in a ferromagnetic material when it is subjected to a changing magnetic field. These losses are a significant consideration in the design and operation of electrical devices such as transformers, inductors, and electric motors, where magnetic materials are used to enhance magnetic flux.

There are two primary components of magnetic losses: hysteresis loss and eddy current loss. Hysteresis loss occurs due to the irreversible rotation of magnetic domains within the material as the magnetic field is cyclically reversed. This process requires energy to overcome the internal friction of the magnetic domains. The amount of hysteresis loss depends on the magnetic properties of the material, such as its coercivity, and the frequency and amplitude of the magnetic field.

Eddy current loss, on the other hand, arises from circulating currents induced within the conductive magnetic material by the changing magnetic flux. These eddy currents flow in closed loops and dissipate energy as heat due to the electrical resistance of the material. Eddy current losses can be reduced by using thin laminations of the magnetic material, insulated from each other, which increases the overall resistance to the flow of eddy currents. The frequency of the AC supply and the resistivity of the material also play crucial roles in determining the magnitude of eddy current losses. Minimizing both hysteresis and eddy current losses is essential for improving the efficiency and reducing the operating temperature of magnetic components.