Magnetic core#Core loss

As iron losses is called the magnetization losses arising in the ferromagnetic components of an electrical machine. Alternating magnetic fields have a constant magnetic reversal result. Without these magnetic fields, these machines can not function. The iron losses are strongly dependent on the quality and on the dimensions ( thickness) of the plates used. The losses are converted to heat. The iron losses are calculated in the no-load test.

Basics

If you place an AC voltage to a coil with an iron core, then arise magnetization losses, which are composed of the magnetic losses, and the after-effects losses. The core losses are made up of the eddy current losses and hysteresis losses the. Eddy current losses in the coil core by means of induced currents, if the core made ​​of an electrically conductive material. Hysteresis losses result from the work that needs to be applied to remagnetize the spool core in the rhythm of the frequency. After-effects losses capture the temporal lag behind the induction of a previous field change. For high flux densities they are negligible compared to the above losses ( hysteresis and eddy current losses ). To mark a sheet quality in practice, these types of losses are combined into a total loss figure v1, 0 and v1, 5. The index denotes the peak value of flux density of 1.0 T and 1.5 T.

The structure of the iron core with insulated panels reduces the eddy current losses.

Measurement of losses

To determine these values ​​are considered as reference conditions:

  • A sinusoidal alternating magnetization B = 1 T or B = 1.5 T.
  • A frequency of 50 Hz

The determination of the loss tangent is done by measurement in the so-called Epstein on standardized sheet specimens.

Calculation

The iron losses of mass is calculated from the nominal operating at different sizes and from:

The different dependencies of the loss shares of the frequency by the frequency factor in the approximation

Taken into account.

With the processing fee

The effect of stamping and other influences can be detected.

Magnetic core Electromagnetic induction Epstein frame
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