Special Electric Machines by Rajini and Nagarajan by Pearson

4

Stepper Motor

Topics Discussed

• ❖ Construction and Types
• ❖ Modes of Excitation
• ❖ Torque Equation
• ❖ Static and Dynamic Characteristics
• ❖ Open and Closed Loop Control
• ❖ Current Suppressor Circuits
• ❖ Multi-stack Stepper Motor

4.1 Introduction

Stepper motors are a class of motors which rotate discretely in angular steps with respect to the sequence of input pulses from the controller. The stepper motors are classified into three types based on rotor construction and they are as follows.

• Variable reluctance stepper motor
• Permanent magnet stepper motor
• Hybrid stepper motor

The use of first developed stepper motor dates back to 1933 by the British Navy, which was a bidirectional variable reluctance type stepper motor (electromagnetic rotor). ...