Number of holes

In electrical engineering, the number of holes is an auxiliary variable for calculating magnetic fields (and thus for determining the torque ) of electrical machines , especially electric motors .

The direction, extent and strength of the resulting magnetic field (field curve ) depend on the way in which the coils generating them are arranged and wound. In addition to the number of pole pairs , the number of strands and the permeability constant, the number of holes is one of the mathematical variables that describe the winding arrangement for the purpose of calculating the magnetic field.

The number of holes q is the number of slots N per number of poles (2 × number of pole pairs p ) and strand m :

${\displaystyle q={N \over 2p\cdot m}}$

literature

• Gregor D. Häberle, Heinz O. Häberle: Transformers and electrical machines in power engineering systems . 2nd Edition. Europa-Lehrmittel, Haan-Gruiten 1990, ISBN 3-8085-5002-3 .