Magnetic circuits

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EXERCISES FOR ELECTRIC POWER SYSTEMS COURSE ENERGY DEPARTMENT, Electrical section Class 1 Magnetic circuits Exercise 1 A magnetic circuit with a single air gap is given in Figure 1.1 . The circuit characteristics are: Cross-section area: /g1827/g3030/g340410 /g1855/g1865/g2870 N1=200 turns Mean core lengths for the various branches of the magnetic circuit: L 1 L 2 L 3 L 4 L 5 L 6 L [mm] 100 30 30 49 49 2 Assume that the core relative permeability is /g2020 /g3045/g340415000 and that the electric circuit is supplied by a continuous current I 1=10 A. Compute the magnetic flux ( /g2038) and the mmf drops in all the branches of the magnetic circuit. Figure 1.1. Magnetic circuit for Exercise 1. Exercise 2 A magnetic circuit with three air gaps is given in Figure 1.2. The circuit characteristics are: Cross-section area: /g1827 /g3030/g3404 10 /g1855/g1865/g2870 N1=200 turns; N 2=400 turns Mean core lengths for the various branches of the magnetic circuit: δ 1 δ2 δ3 L [mm] 1.5 2 2.5 Assuming that the core relative permeability is /g2020 /g3045→ ∞ , compute the self-inductance and the mutual- inductance parameters for the given magnetic circuit. Figure 1.2. Magnetic circuit for Exercise 2. I1 L1 L2 L3 L5 L4 L6 N1 I1 N1 δ1 δ2 δ3 I2N2