A brief introduction to frequency converters and servo drives

The concept and working principle of frequency converter

A frequency converter is a power regulation device that can convert the frequency and voltage of a power source (usually AC power) into a variable output signal, thereby achieving the purpose of driving the motor to adjust the speed. The main function of the frequency converter is to control and adjust the motor speed by adjusting the output frequency and voltage of the motor. The frequency converter can also achieve a variety of protection functions, such as overload protection, short circuit protection, overheating protection, etc.

The working principle of the inverter is to convert the DC power of the mobile phone charger into waveform power, so that the motor can use the control system in the inverter to adjust the frequency and voltage, thereby realizing the control and regulation of the motor. The inverter realizes fast and efficient power inversion and motor drive control through digital modulation technology, making it have the advantages of high efficiency, energy saving, precise control and compact structure. At the same time, the inverter can also perform automatic adjustment and fault detection through the feedback control system to ensure the safety and reliability of the motor.

Frequency converter control method

A frequency converter is an electronic device used to control the speed and torque of a motor. It is usually used to save energy and improve system efficiency. It has a variety of control methods, including:

1. V/F control: Control the speed of the motor by changing the voltage and frequency output by the inverter. It is often used in situations where precise control is not required.

2. Vector control: By controlling the current and magnetic field of the motor to adjust the speed and torque of the motor in real time, high-precision control can be achieved.

3. Flow control: Control the speed of the motor by measuring variables such as flow rate and pressure. It is suitable for the control of circulating fluid systems.

4. Encoder control: By installing an encoder to measure the actual speed and position of the motor, precise control and closed-loop control can be achieved.

5. PLC control: integrated PLC controller and frequency converter can realize advanced control, automation and remote monitoring.

Functional features of frequency converter

The frequency converter is an electronic control device with variable frequency and controllable voltage. It is widely used in modern industrial production due to its unique functions and characteristics. The following are the functional characteristics of the frequency converter:

1. Adjustable output frequency: The inverter can adjust the frequency (Hz) of the output current as required to achieve control of the drive equipment.

2. Energy saving and consumption reduction: The inverter adjusts the motor speed and controls the output power, effectively avoiding unnecessary losses caused by long-term operation of the motor under traditional electrical control methods.

3. Enhanced equipment control: The frequency converter can not only realize speed control, but also realize a variety of motion control methods, thereby enhancing the control performance of the equipment.

4. Reduce the starting current of the equipment: The inverter can achieve voltage up and down regulation and soft start through means such as the stepless transformer before the inverter, reduce the current impact when the equipment is started, and improve the reliability and service life of the equipment.

5. Improve product quality: The inverter can effectively control the production speed and quality of the product, avoiding poor product quality caused by unstable motor speed during the production process.

6. Reduce operating noise: The frequency converter can reduce operating noise by adjusting the speed of the motor, greatly reducing noise pollution at the work site.

7. Increase equipment life: The inverter's soft start, output overload, overvoltage and other protection measures can effectively prevent damage to motor and electrical components, thereby ensuring the life and reliability of the equipment.

The concept and working principle of servo drive

A servo drive is an electrical device used to control the position, speed, acceleration and other parameters of a servo motor to achieve precise control. A servo drive usually includes a power amplifier, an encoder feedback device, a control circuit and other components.

Its working principle is: the controller sends a motion command to the servo driver. After receiving the command, the servo driver calculates according to the motor position information returned by the encoder feedback device, drives the motor to rotate, and through feedback and control, tracks and adjusts the position, speed and acceleration of the motor output in real time to achieve the purpose of accurately controlling the motor rotation.

The servo drive is characterized by its ability to output high-precision motion control signals, and has the advantages of fast response, high-speed motion, and high precision. It is often used in automated production lines, machine tools, automated warehousing equipment and other fields.

Servo drive control method

The control methods of servo drives are generally divided into the following categories:

1. Position control: The purpose of control is achieved by controlling the position of the servo motor. Common control methods include basic position control, tracking control, etc.

2. Speed ​​control: The purpose of control is achieved by controlling the movement speed of the servo motor. Common control methods include current loop speed control, position speed control, etc.

3. Torque control: The purpose of control is achieved by controlling the output torque of the servo motor. Common control methods include current loop torque control, position torque control, etc.

4. Dynamic control: The purpose of control is achieved by controlling factors such as the acceleration and deceleration of the servo motor. Common control methods include acceleration control, deceleration control and damping control.

5. Dynamic compensation control: The purpose of control is achieved by controlling the dynamic compensation amount of the servo motor. Common control methods include loop dynamic compensation control, analog predictive control, etc.

The above are common servo drive control methods. Different control methods are suitable for different application scenarios. Selecting the corresponding control method according to actual needs can improve the performance of the control system.

Functional characteristics of servo drive

A servo drive is a device that controls the movement of a motor and has the following features:

1. Precise control: Servo drives can precisely control the position, speed, and acceleration of the motor to achieve high-precision motion control.

2. Fast response: The servo drive has fast response capability and can react to control signals within milliseconds.

3. Large torque output: The servo drive can provide large torque output, allowing the motor to withstand relatively large loads.

4. Automatic control: The built-in electronic controller of the servo drive can realize automatic control, reduce manual intervention and improve machine working efficiency.

5. High-precision position feedback: Servo drives often use high-precision position feedback technology, such as encoders, serial numbers, etc., to obtain more accurate position information.

6. Programmable control: The servo drive can be programmed and controlled according to different application requirements to adapt to various complex motion control requirements.