The Stepper Permanent Magnet (or Stepper Motor PM) component models a two-phase permanent magnet stepper machine. The winding resistances and inductances of the two phase windings are identical. The losses in the winding resistances only are taken into account; saturation is not modeled.

$J\stackrel{\.}{\mathrm{\omega }}\+B\mathrm{\omega }\=-K_m{i}_a\sin \left(\mathrm{Nr}\mathrm{\theta }\right)\+K_m{i}_b\cos \left(N_r\mathrm{\theta }\right)-\mathrm{\tau }$

$L\stackrel{\.}{i_a}\+R{i}_a\=v_{a_p}-v_{a_n}\+K_m\mathrm{\omega }\sin \left(N_r\mathrm{\theta }\right)$

$L\stackrel{\.}{i_b}\+R{i}_b\=v_{b_p}-v_{b_n}-K_m\mathrm{\omega }\cos \left(N_r\mathrm{\theta }\right)$

$\mathrm{\omega }\=\stackrel{\.}{\mathrm{\theta }}$

$i_a\=i_{a_p}\=-i_{a_n}$

$i_b\=i_{b_p}\=-i_{b_n}$

$\mathrm{\theta }\={\mathrm{\phi }}_{\mathrm{rflange}}$

$\mathrm{\tau }\={\mathrm{\tau }}_{\mathrm{rflange}}$