Although servo motors are the mainstream motor drive method in the market, stepper motors have a greater advantage than servo motors in certain situations. Therefore, it is still necessary for electronic engineers to understand stepper motors. This article will discuss the working principle, classification and characteristics of stepper motors in detail.
A stepper motor is a type of induction motor. Its working principle is to use electronic circuits to program DC circuits to supply power in a time-sharing manner. Multi-phase timing control current is used to power the stepper motor, which is essential for its normal operation. The driver is responsible for supplying power to the stepper motor in a time-sharing manner.
Although stepper motors are widely used, they cannot be used like ordinary DC or AC motors under normal conditions. They require a control system consisting of dual-ring pulse signals and power drive circuits to function. Therefore, using stepper motors effectively is not easy; it involves a great deal of expertise in mechanics, electrical engineering, electronics, and computers.
Stepper motors, as actuators, are one of the key products in mechatronics and are widely used in various automated control systems. With the development of microelectronics and computer technology, the demand for stepper motors is increasing daily, and they are used in various sectors of the national economy.
Commonly used stepper motors include reactive stepper motors (VR), permanent magnet stepper motors (PM), hybrid stepper motors (HB), and single-phase stepper motors.
Permanent magnet stepper motor:
Permanent magnet stepper motors are generally two-phase, with smaller torque and size, and a step angle of typically 7.5 degrees or 15 degrees. They have high output torque and good dynamic performance, but a large step angle.
reactive stepper motor:
Reactive stepper motors are generally three-phase and can achieve high torque output. The step angle is generally 1.5 degrees, but the noise and vibration are very large. The rotor magnetic circuit of the reactive stepper motor is made of soft magnetic material, and the stator has multi-phase excitation windings, which generate torque by utilizing the change of magnetic permeability.
Reactive stepper motors have a simple structure, low production cost, and small step angle, but poor dynamic performance.
Hybrid stepper motor:
Hybrid stepper motors combine the advantages of reactive and permanent magnet stepper motors. They have small step angles, high output power, and good dynamic performance, making them the highest-performing stepper motors currently available. They are also called permanent magnet induction stepper motors and are available in two-phase and five-phase versions: two-phase step angles are 1.8 degrees, while five-phase step angles are generally 0.72 degrees. This type of stepper motor is the most widely used.
