A stepping motor can be divided into its structural form reactive type stepping motor (VariableReluctance, VR), PM type stepping motor PermanentMagnet, PM), hybrid stepping motor (HybridStepping, HS), a single-phase stepping motor, and other types of flat stepping motor, the stepping motor employed in the country to react mainly stepping motor. Are closely related with the performance control operation of the stepping motor, the stepping motor control system from the control point of view, it can be divided into the following three categories: open-loop control, closed-loop control system, a semi-closed loop control system. Semi closed loop control system in practical use is generally classified as open or closed loop system. 
Reaction formula: windings on the stator, the rotor of a soft magnetic material. Simple structure, low cost, small step angle up to 1.2 °, but poor dynamic performance, low efficiency, heat, difficult to guarantee reliability. 
Permanent magnet: a PM type stepping motor rotor permanent magnet material, the number of poles of the rotor and the poles of the stator of the same. Which is characterized by good dynamic performance, the output torque, this motor but poor accuracy, a large torque-angle step (typically 7.5 ° or 15 °). 
Hybrid: a hybrid stepping motor integrated permanent magnet and reactive advantages, multi-phase stator winding, with permanent magnet material on the rotor, the rotor and stator teeth are a plurality of steps to improve the accuracy of the moment. Which is characterized by a large output torque, good dynamic performance, step angle is small, but the complex structure, relatively high cost. 
Press the stator windings to points, a total of two-phase, three-phase and five equal series. The most popular is the two-phase hybrid stepper motors, accounting for more than 97% market share, the reason is the high cost, coupled with the broken drive to good effect. The basic step angle of pitch motor kinds 1.8 ° / step, half-step coupled with the drive step angle is reduced to 0.9 °, the coupled drive segments which can be subdivided step angle up to 256 fold (0.007 ° / Micro step). Manufacturing precision due to friction and other reasons, the actual control accuracy is slightly lower. The same can be equipped with a stepper motor drive different segments to change the accuracy and effectiveness.