A 3-phase, 3 stack, variable reluctance stepper motor has 20 pole on each rotor and stator stack. The step angle of this stepper motor is

Concept:

Speed of stepper motor \( = \frac{{β f}}{{360}}\)

Step angle in a stepper motor is given by

\({\rm{\beta }} = \frac{{360}}{{{\rm{m}}{{\rm{P}}_{\rm{r}}}}} \)

\(β = \frac{{\left( {{P_s} - {P_r}} \right)}}{{{P_s}{P_r}}} \times 360\)

Where,

Ps is the number of stator poles

Pr is the number of rotor poles

f is stepping rate

m is number of stack

Calculation:

Given-

m = 3, N_r = 20

Now step angle can be calculated as

\({\rm{\beta }} = \frac{{360}}{{{\rm{m}}{{\rm{P}}_{\rm{r}}}}} = \frac{{360}}{{3{\rm{x}}20}} = {6^\circ}\)