Core

Description

Core losses can be separated into eddy current and hysteresis losses. The total core losses can thus be expressed as

  P = PRef * (ratioHysteresis * (wRef / w) + 1 - ratioHysteresis) * (V / VRef)^2

where w is the actual angular remagnetization velocity and V is the actual voltage. The term ratioHysteresis is the ratio of the hysteresis losses with respect to the total core losses for the reference voltage and frequency.

In the current implementation hysteresis losses are not considered since complex numbers are not provided in Modelica. Therefore, implicitly ratioHysteresis = 0 is set. For the voltage and frequency range with respect to Fig. 1, the dependency of total core losses on the parameter ratioHysteresis is depicted in Fig. 2. The current implementation has thus the drawback over a model that considers ratioHysteresis > 0:

• underestimation of the losses in the constant field region (w < wRef)
• overestimation of the losses in the field weakening region (w > wRef)

Fig. 1: Voltage versus angular velocity

Fig. 2: Core losses versus angular velocity with parameter ratioHysteresis

Note

In the current implementation it is assumed that ratioHysteresis = 0. This parameter cannot be changed due to compatibility reasons.

See also

Core loss parameters