Parallel Magnetic Circuit
Definition of Parallel Magnetic Circuit
A parallel magnetic circuit is defined as a magnetic pathway with two or more branches for magnetic flux, analogous to a parallel electric circuit. Such circuits feature multiple flux paths with varying cross-sectional areas and materials, each potentially composed of different magnetic components.
Parallel Magnetic Circuit Analysis
The figure above depicts a parallel magnetic circuit, where a current-carrying coil is wound around the central limb AB. This coil generates a magnetic flux φ₁ in the central limb, which travels upward and splits into two parallel paths: ADCB and AFEB. The path ADCB conducts flux φ₂, while AFEB carries flux φ₃. As evident from the circuit:
Parallel Magnetic Circuit Characteristics
The two magnetic paths ADCB and AFEB form a parallel magnetic circuit, where the ampere-turns (ATs) required for the entire parallel circuit equal the ampere-turns needed for any single branch.
As is known, reluctance is defined as：
Parallel Magnetic Circuit MMF Calculation
Thus, the total magnetomotive force (MMF) or ampere-turns required for a parallel magnetic circuit equals the MMF of any single parallel path, as all branches experience the same applied MMF.
Incorrect Notation Clarification:
The total MMF is not the sum of individual paths (a common misconception). Instead, since parallel magnetic paths share the same applied MMF, the correct relation is:
Total MMF = MMF for path BA = MMF for path ADCB = MMF for path AFEB
Where φ1. Φ2, φ3 is the flux and S1, S2, S3 are the reluctances of the parallel path BA, ADCB and AFEB respectively.
