Detailed explanation of the function and parameters of the servo drive

Servo driver, also known as servo controller and servo amplifier, is a part of the servo system and is mainly used in high-precision positioning systems. It is a controller used to control servo motors. The motor is controlled to achieve high-precision transmission system positioning.

1. The role and function of the servo drive

A servo driver is a controller that drives a servo motor to generate power for the equipment to operate normally. There are many types of functional subdivisions, including:

1. Parameters can be grouped and set, and the control mode can be switched arbitrarily.
2. Control power AC input, wide voltage input that can be set.
3. Instantaneous power failure and fast shutdown protection function.
4. Regenerative braking and dynamic braking functions.
5. Absolute value system voltage monitoring, low voltage warning function.
6. The debugging software supports parameter management, monitoring and oscilloscope functions.

 

2. Detailed explanation of servo drive parameters

In automation equipment, servo motors are often used. Servo motors are generally controlled by servo drivers. To use servo drivers, you need to know some of its parameters.

 

1. Position proportional gain

Set the proportional gain of the position loop regulator. The larger the setting value, the higher the gain and the greater the stiffness. Under the condition of the same frequency command pulse, the position hysteresis will be smaller, but if the value is too large, it may cause oscillation or overshoot. The parameter value Determined by the specific servo system model and load conditions.

 

2. Position feedforward gain

Set the feed-forward gain of the position loop. The larger the set value, the smaller the position lag under any frequency command pulse, the larger the feed-forward gain of the position loop, and the higher the high-speed response characteristics of the control system, but it will make the The position of the system is unstable and prone to oscillation. Therefore, when a high response characteristic is not required, this parameter is usually set to 0 (indicating range: 0~100%).

 

3. Speed proportional gain

Set the proportional gain of the speed regulator, the larger the setting value, the higher the gain and the greater the stiffness. The parameter value is determined according to the specific servo drive system model and load value. In general, the larger the load inertia, the larger the setting value. Under the condition that the system does not generate oscillation, try to set a larger value. Certainly.

 

4. Speed integral time constant

Set the integral time constant of the speed regulator, the smaller the setting value, the faster the integral speed. The parameter values are determined according to the specific servo drive system model and load conditions. In general, the greater the load inertia, the greater the setting value. Under the condition that the system does not oscillate, try to set a smaller value.

 

5. Speed feedback filter factor

Set the characteristics of the speed feedback low-pass filter. The larger the value, the lower the cut-off frequency and the smaller the noise generated by the motor. If the load inertia is large, the setting value can be appropriately reduced. If the value is too large, the response will slow down and may cause oscillation; the smaller the value, the higher the cutoff frequency and the faster the speed feedback response. If higher speed response is required, the setting value can be appropriately reduced.

 

6. Maximum output transfer setting

Set the internal torque limit value of the servo motor. The set value is the percentage of the rated torque. At any time, this limit is valid for the positioning completion range. Set the positioning completion pulse range in the position control mode. This parameter provides the basis for the driver to judge whether the positioning is completed in the position control mode, when the number of remaining pulses in the position deviation counter.

When it is less than or equal to the set value of this parameter, the drive considers that the positioning has been completed, and the in-position switch signal is ON, otherwise it is OFF. In the position control mode, the output position positioning completion signal, the acceleration and deceleration time constant, the set value is the acceleration time of the motor from 0~2000r/min or the deceleration time from 20000r/min, the acceleration and deceleration characteristics are linear and the speed is reached , set the arrival speed. In non-position control mode, if the motor speed exceeds the set value, the speed arrival switch signal is ON, otherwise it is OFF.