The Stepper Variable Reluctance Motor (or Stepper Motor VR) component models a two-phase variable reluctance 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.

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

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

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

$i_a\=i_{{\mathrm{pos}}_1}\=-i_{{\mathrm{neg}}_1}{i}_b\=i_{{\mathrm{pos}}_2}\=-i_{{\mathrm{neg}}_2}{i}_c\=i_{{\mathrm{pos}}_3}\=-i_{{\mathrm{neg}}_3}$

$v_{a_p}\=v_{{\mathrm{pos}}_1}{v}_{a_n}\=v_{{\mathrm{neg}}_1}{v}_{b_p}\=v_{{\mathrm{pos}}_2}{v}_{b_n}\=v_{{\mathrm{neg}}_2}{v}_{c_p}\=v_{{\mathrm{pos}}_3}{v}_{c_n}\=v_{{\mathrm{neg}}_3}$

$J\stackrel{\.}{\mathrm{\omega }}\+B\mathrm{\omega }\=\frac{\mathrm{-1}}{2}{i}_a^2\left(\frac{1}{2}{L}_{\max }-\frac{1}{2}{L}_{\min }\right)\sin \left(N_r\mathrm{\theta }\right)N_r\+\frac{1}{2}{i}_b^2\left(\frac{1}{2}{L}_{\max }-\frac{1}{2}{L}_{\min }\right)\sin \left(N_r\mathrm{\theta }\+\frac{1}{3}\mathrm{\pi }\right)N_r-\frac{1}{2}{i}_c^2\left(\frac{1}{2}{L}_{\max }-\frac{1}{2}{L}_{\min }\right)\cos \left(N_r\mathrm{\theta }\+\frac{1}{6}\mathrm{\pi }\right)N_r-\mathrm{\tau }$

$\left(\frac{1}{2}{L}_{\max }\+\frac{1}{2}{L}_{\min }\+\left(\frac{1}{2}{L}_{\max }-\frac{1}{2}{L}_{\min }\right)\cos \left(N_r\mathrm{\theta }\right)\right){\stackrel{\.}{i}}_a\+R{i}_a\=v_{a_p}-v_{a_n}\+i_a\left(\frac{1}{2}{L}_{\max }-\frac{1}{2}{L}_{\min }\right)\sin \left(N_r\mathrm{\theta }\right)N_r\stackrel{\.}{\mathrm{\theta }}$

$\left(\frac{1}{2}{L}_{\max }\+\frac{1}{2}{L}_{\min }-\left(\frac{1}{2}{L}_{\max }-\frac{1}{2}{L}_{\min }\right)\cos \left(N_r\mathrm{\theta }\+\frac{1}{3}\mathrm{\pi }\right)\right){\stackrel{\.}{i}}_b\+R{i}_b\=v_{b_p}-v_{b_n}-i_b\left(\frac{1}{2}{L}_{\max }-\frac{1}{2}{L}_{\min }\right)\sin \left(N_r\mathrm{\theta }\+\frac{1}{3}\mathrm{\pi }\right)N_r\stackrel{\.}{\mathrm{\theta }}$

$\left(\frac{1}{2}{L}_{\max }\+\frac{1}{2}{L}_{\min }-\left(\frac{1}{2}{L}_{\max }-\frac{1}{2}{L}_{\min }\right)\sin \left(N_r\mathrm{\theta }\+\frac{1}{6}\mathrm{\pi }\right)\right){\stackrel{\.}{i}}_c\+R{i}_c\=v_{c_p}-v_{c_n}\+i_c\left(\frac{1}{2}{L}_{\max }-\frac{1}{2}{L}_{\min }\right)\cos \left(N_r\mathrm{\theta }\+\frac{1}{6}\mathrm{\pi }\right)N_r\stackrel{\.}{\mathrm{\theta }}$