Effects of magnetic properties of steel on flux response

It has been shown that the relative magnetic permeability μs and the electric resistivity ρ of magnetic steel have serious effects on the flux response of electromagnetic actuators used in automobiles. These effects are quantitatively examined by a magnetic field calculation based on the finite-element method. Also, some criteria for selecting optimum magnetic steel are proposed in view of the minimum allowable μs and ρ. It is shown that when an electromagnetic actuator is used in a linear range both μs and ρ must be large. The minimum allowable μs and ρ are 1000 and 72 μΩ-cm, respectively. When the actuator is used in a nonlinear range, B₂₀ must be large enough to broaden the linear range