Advantages and Disadvantages of Servo Motor Speed ​​Regulation Methods

Servo motor is a popular type of equipment in the machinery industry. It is the engine that controls the operation of mechanical components in the servo system. However, this motor will occasionally overheat during operation. We introduced the causes and solutions to overheating of the servo motor in detail last time. So how to adjust the speed of the servo motor? Next, the editor will introduce in detail the advantages and disadvantages of the servo motor speed adjustment method!

After engineers select the servo and driver models based on load, torque, etc., in specific applications, it also involves the determination and setting of the servo motor speed parameter. It is recommended to adjust the servo motor speed by adjusting the pulse frequency of the input driver and the subdivision parameters of the driver. In fact, it is to control the number of steps of the servo per unit time.

The advantages and disadvantages of conventional servo motor speed regulation methods are as follows:

1. Commutator motor speed regulation

Advantages: ① It has the simple structure of AC synchronous motor and good speed regulation performance of DC motor; ② It uses the power supply voltage at low speed and the back electromotive force of servo motor at high speed for natural commutation, and it operates reliably; ③ No additional slip loss, high efficiency, It is suitable for starting and speed regulating high-speed and large-capacity synchronous motors.

Disadvantages: This method of speed regulation has low overload capacity, and the capacity of the original motor cannot be fully utilized.

2. Stator voltage regulation and speed regulation

Advantages: ① The circuit is simple, the device is small, and the price is cheap; ② It is easy to use and maintain.

Disadvantages: ① The slip loss is increased during the speed regulation process, which causes the rotor to heat up and the efficiency is low; ② The speed regulation range is relatively small; ③ High slip motors are required, such as specially designed torque motors, so the characteristics are soft and generally Suitable for asynchronous motors below 55kW.

3. Rotor string resistance speed regulation

Advantages: ① The technical requirements are low and easy to master; ② The equipment cost is low; ③ There is no electromagnetic harmonic interference.

Disadvantages: ① A series of cast iron resistors can only perform step-by-step speed regulation. If liquid resistors are used for stepless speed regulation, the requirements for maintenance and upkeep are higher; ② The additional slip power during the speed regulation process is all converted into losses in the form of heating of the series resistors, and the efficiency is low; ③ The speed regulation range is not large.

4. Electromagnetic slip clutch speed regulation

Advantages: ① Simple structure, small control device capacity and low price; ② Reliable operation and easy maintenance; ③ No harmonic interference.

Disadvantages: ① Large speed loss, because the slip of the electromagnetic slip clutch itself is large, so the speed of the output shaft is only 80% to 90% of the synchronous speed of the servo motor; ② During the speed regulation process, all slip power is converted into heat energy. loss, low efficiency.