What is the performance difference between AC servo motor and stepping motor?

With the continuous development and updating of technology, the whole society is undergoing industrial adjustment, and motors are widely used in all walks of life. There are two types of motors currently available in the market, one is stepping motor, and the other is AC servo motor. Today, the technical engineer of CIIC Electric will introduce the performance difference between AC servo motor and stepping motor?

Performance difference between AC servo motor and stepping motor:

1. Different control precision

The step angle of two-phase hybrid stepping motor is generally 1.8 °, and that of five phase hybrid stepping motor is generally 0.72 ° and 0.36 °. There are also some high-performance stepping motors with smaller step angle. The control accuracy of the AC servo motor is guaranteed by the rotary encoder at the rear end of the motor shaft. The standard encoder of KINCO servo motor in China is 8000inc/rev.

2. Different low-frequency characteristics

Stepping motor is prone to low-frequency vibration at low speed. The vibration frequency is related to the load condition and the performance of the driver. It is generally considered that the vibration frequency is half of the no-load jump frequency of the motor. The AC servo motor runs very smoothly and will not vibrate even at low speed.

3. Different torque frequency characteristics

The output torque of stepping motor decreases with the increase of speed, and the torque drops sharply at higher speed, so its * high working speed is generally 300~600 RPM. The servo motor is different. It can output rated torque within the rated speed (generally 2000RPM or 3000RPM).

4. Different overload capacities

Stepping motor generally does not have overload capacity, while servo motor has strong overload capacity, which can be used to overcome the inertia moment of inertia load at the moment of starting.

5. Different operation performance

The control of stepping motor is open-loop control. If the starting frequency is too high or the load is too large, it is easy to lose step or lock up the rotor. If the speed is too high and the stop time is short, it is easy to have overshoot. To ensure the control accuracy, the problems of speed rise and speed fall should be handled properly. The servo drive system adopts closed loop control. The driver can directly sample the feedback signal of the motor encoder. The position loop and speed loop are formed internally. Generally, there is no step loss or overshoot of the stepper motor, and the control performance is more reliable.

6. Different speed response performance

It takes hundreds of milliseconds for the stepper motor to accelerate from static to working speed (usually hundreds of revolutions per minute). The acceleration time of servo motor usually only takes a few milliseconds or tens of milliseconds. It is often used in applications requiring quick start and stop.

What is the performance difference between AC servo motor and stepping motor? Through the above introduction, I hope it will be helpful to everyone. From the above analysis, it can be seen that AC servo motors are better than stepping motors in many aspects of performance. However, in the design process of the control system, it is necessary to comprehensively consider the control requirements, cost and other factors, and select the appropriate motor.