Electrical Engineering ⇒ Topic : Parallel Magnetic Circuit-

Parallel Magnetic Circuit:-

A magnetic circuit which has more than one path for flux is called a parallel magnetic circuit. It can just be compared to a parallel electric circuit which has more than one path for electric current.

The concept of parallel magnetic circuit is illustrated in Fig. (a). Here a coil of N turns wounded on limb AF carries a current of I amperes. The flux Φ₁ set up by the coil divides at B into two paths, namely ;

                                                                             figure (a)

(1) flux Φ₂ passes along the path BE

(2) flux Φ₃ follows the path BCDE

          Clearly,Φ₁  = Φ₂ + Φ₃

The magnetic paths BE and BCDE are in parallel and form a parallel magnetic circuit. The AT required for this parallel circuit is equal to AT required for any *one of the paths.

Let                       S₁ = reluctance of path EFAB

                             S₂ = reluctance of path BE

                             S₃ = reluctance of path BCDE

Total m.m.f. required = m.m.f. for path EFAB + m.m.f. for path BE or path BCDE

                         or NI = Φ₁S₁  + Φ₂S₂

                                  = Φ₁S₁ + Φ₃S₃

The reluctances S₁, S₂ and S₃ must be determined from a calculation of l/aμ₀μ_r for those paths of the magnetic circuit in which Φ₁ + Φ₂ + Φ₃ exist respectively.