What is the difference between a three phase asynchronous motor and a stepper motor

Asynchronous motors. Induction motors) work by generating an induced current in the rotor through the rotating magnetic field of the stator.

This results in an electromagnetic torque, and no magnetic field is directly generated in the rotor. Therefore, the rotational speed of the rotor must be less than the synchronous speed (there is no such difference, i.e., the slip rate.

There is no rotor induced current), which is why it is called an asynchronous motor.

Stepper motors. It is an actuator that converts electrical impulses into angular displacements. When the stepper driver receives a pulse signal.

It drives the stepper motor to rotate at a fixed angle (called the "step angle") in a set direction, and its rotation is to run step by step at a fixed angle. The angular displacement can be controlled by controlling the number of pulses, so as to achieve the purpose of accurate positioning; At the same time, the speed and acceleration of the motor rotation can be controlled by controlling the pulse frequency.

So as to achieve the purpose of speed regulation. The stepper motor can be used as a special motor for control, and it is widely used in various open-loop control due to its characteristics of no accumulated error (accuracy of 100%).

Nowadays, the more commonly used stepper motors include reactive stepper motors (VR), permanent magnet stepper motors (PM), hybrid stepper motors (HB) and single-phase stepper motors.

The permanent magnet stepper motor is generally two-phase, the torque and volume are small, and the stepping angle is generally 15 degrees;

Reactive stepper motors are generally three-phase, which can achieve large torque output, and the stepping angle is generally degrees, but the noise and vibration are very large. The rotor magnetic circuit of a reactive stepper motor is a soft magnetic material.

It is made with a multi-phase excitation winding on the stator and uses the change in magnetic conductivity to generate torque.

Hybrid stepper motor refers to a mixture of the advantages of permanent magnet and reactive type. It is further divided into two phases and five phases: the two-phase stepping angle is generally degrees, while the five-phase stepping angle is generally degrees. This type of stepper motor is the most widely used.

Three-phase step motor and stepper motor: mainly three-phase step motor AC braking performance is poor, stability difference. Stepper motor: DC control, high precision, good braking and other advantages, mostly used with machine tool control.

1. The structure is different. The rotor of a synchronous motor has windings and there are brushes to supply power to the rotor, whereas the rotor of an asynchronous motor has no windings and no brushes.

2. The principle is different. Both synchronous and asynchronous refer to the relationship between the speed of the motor and the frequency of the power supply. The speed of the synchronous motor is synchronized with the frequency of the power supply AC. The speed of the asynchronous motor is not synchronized with the frequency of the alternating current of the power supply.

3. The application is different. In terms of application, synchronous motors are used in occasions with strict speed requirements, and they are also expensive. Asynchronous motors are commonly used in general occasions and are inexpensive.

Three-phase asynchronous motor is a kind of induction motor, is a kind of motor powered by 380V three-phase AC current at the same time, because the rotor and stator of the three-phase asynchronous motor rotate in the same direction, different speeds, there is a slip rate, so it is called a three-phase asynchronous motor. The rotation speed of the rotor of the three-phase asynchronous motor is lower than the rotation speed of the rotating magnetic field, and the rotor winding generates electromotive force and current due to the relative motion between it and the magnetic field, and interacts with the magnetic field to generate electromagnetic torque to achieve energy conversion.

The driving power supply of the stepper motor is composed of a variable frequency pulse signal source, a pulse distributor and a pulse amplifier, and the driving power supply provides pulse current to the motor winding. The running performance of the stepper motor depends on the good coordination between the motor and the drive power supply.

The advantages of stepper motor are that there is no cumulative error, simple structure, easy to use and maintain, low manufacturing cost, and the ability of stepper motor to drive load inertia is large, which is suitable for small and medium-sized machine tools and places where speed accuracy requirements are not high.

Compared with stepper motors, three-phase asynchronous motors have good running performance and can save various materials.

The three-phase asynchronous motor cooling fan is fixed on the shaft of the motor, which is the same as the speed of the motor, and when running at low frequency, the fan also runs at low speed, the cooling capacity is greatly reduced, and the heat generated by the motor cannot be dissipated, and the motor will be burned in serious cases.

In addition, the structure and voltage resistance of the inverter motor have been specially designed and strengthened to adapt to the situation of high speed and high harmonics.

The motor is divided into ordinary motors and variable frequency motors, the reason why it is called variable frequency motors is mainly different from the appearance of ordinary motors is that the variable frequency motor is added to the centrifugal fan for forced heat dissipation, which ensures that the motor dissipates well at low frequency and high frequency, and the internal structure of the variable frequency motor can adapt to high-frequency operation, and the specific frequency range that can be operated can be seen in the nameplate.

Ordinary motors are generally only allowed to run below 50Hz.

Three-phase asynchronous motor (triple-phase asynchronous motor) is a kind of motor that is connected to 380V three-phase AC power supply (phase difference 120 degrees) at the same time, because the rotor and stator of the three-phase asynchronous motor rotate in the same direction and at different speeds, and there is a slip rate, so it is called a three-phase asynchronous motor. Xiangtan Electric Machinery Factory.

Three-phase asynchronous motor has the advantages of high efficiency, energy saving, low noise, low vibration and reliable performance, and can be used for driving different types of machinery: such as ventilators, compressors, pumps, crushers, cutting machine tools and other equipment, and can be used as prime mover for coal mines, machinery industry, power plants and various industrial and mining enterprises. Thanks for the reference.

Hope it helps.

1. The rotational speed is different from the rotational speed of the magnetic field. If the rotation speed of the rotor is the same as that of the stator, it is called a synchronous motor, and if it is inconsistent, it is called an asynchronous motor.

2. The rotor speed is different. When the number of pole pairs is constant, there is a strict relationship between the speed and frequency of the motor, and the rotor speed of the asynchronous motor is always less than that of the synchronous motor when it is working.

3. Different use scenarios. In terms of usage scenarios, synchronous motors are used in occasions with strict speed requirements, and they are also expensive. Asynchronous motors are commonly used in general occasions and are inexpensive.

Comparison of advantages and disadvantages of three-phase asynchronous motor + stepper motor + DC motor.

The advantages of three-phase asynchronous motors are: cheap and simple operation and structure, widely used in a variety of mechanical equipment. The disadvantages are also obvious, the operation and structure of the simple macro single hall has not led to its work efficiency in all aspects can not meet the requirements.

The stepper motor can realize precise positioning control and is widely used in displacement precise positioning system; However, the control is more complex than that of DC motors; DC motor control is relatively simple, but the positioning accuracy is not high, and it can be used in systems with high speed requirements and low displacement positioning.