What is the difference between servo and frequency converter?

What is the difference between servo and frequency converter? The following frequency converter manufacturer SOWAKAM will introduce to you the difference between servo and frequency converter:

The two definitions are different:

The frequency converter is an electric energy control device that uses the disconnection function of power semiconductor devices to convert industrial frequency power to another frequency. It can realize soft start of AC asynchronous motors, variable frequency speed regulation, improve operating accuracy, change power factors, etc. .

A servo system is an automatic control system that enables the position, location, status and other outputs of an object to follow any changes in the input target (or given value). The main task is to amplify power, transform and adjust according to the requirements of the control command, making the output torque, speed and position control of the drive device very flexible and convenient.

The working principles of the two are different:

The speed regulation principle of the frequency converter is mainly affected by four factors: asynchronous motor speed n, asynchronous motor frequency f, motor slip s, and motor pole number p. The rotation speed n is proportional to the frequency f. As long as the frequency f is changed, the speed of the motor can be changed. Frequency control is achieved by changing the motor power frequency. It mainly uses the AC-DC-AC method, converting the power frequency AC power into DC power through a rectifier, and then converting the DC power into frequency. The working principle of the servo system is based on the open-loop control of the AC and DC motors. The speed and position signals are fed back to the drive through the rotary encoder, rotary transformer, etc. for closed-loop negative feedback PID adjustment control. Different overload capacities

Servo drives generally have an overload capacity of 3 times, which can be used to overcome the inertia torque of the inertial load at the moment of startup. Frequency converters generally allow an overload of 1.5 times.

Accuracy control is different

The control accuracy of the servo system is much higher than that of the frequency conversion system, which is usually guaranteed by the rotary encoder at the rear end of the motor shaft. The control accuracy of some servo systems even reaches 1:1000.

Different application situations

Frequency conversion control and servo control are two types of control. The former belongs to the field of transmission control, and the latter belongs to the field of motion control. One is to meet the requirements of general industrial applications and pursue low cost for applications that do not require high performance indicators. The second is to pursue high precision, high performance and high response.

Different acceleration and deceleration performance

The servo motor is processed from a static state to 2000r/min under no load, and the use time does not exceed 20ms. The acceleration time of the motor is related to the inertia of the motor shaft and the load. The greater the inertia, the longer the acceleration time.