Inductance And Magnetic Energy


In Section 1.3, we introduced inductance, L, as an electric circuit element. Alternatively, we may relate inductance to magnetic circuit (or field) quantities. Thus, we redefine the inductance of an N-turn co il as the flux linkage, ג , per unit current:

          (formula 5)

In (5),  Φ is the flux through each of the turns (or, the mean flux per turn). The unit of inductance is the henry (H).

For a magnetic circuit having n distinct coils, we may define n2 inductances by
(Formula 6)

where Np is the number of turns in the pth coil and where kpq, the coupling coefficient between the pth and qth coils, is defined as the fraction of the flux produced by the qth coil that links the pth coil. For p q,

Lpq is called the mutual inductance between coils p and q;  for p = q, Lpp is the self-inductance of coil p. If the n coils carry currents i1, i2,...... ..., im    it may be shown that the energy stored in the inductances is given by

(Formula 7)

Further, it may be shown that the same energy may be expressed, in terms of magnetic field quantities B and H, as


 (Formula 8 )

Keywords : Inductance, Magnetic, Energy, Magnetic, Induction, Transformer, Transformation, Electrical, Electronic
Writer : delon  |
16 Mar 2006 Thr   
No Comments