Why is inertia matching necessary when selecting servo motors?

Inertia matching is very important for the selection of servo motors, mainly because inertia matching can ensure system stability and control accuracy, while also improving response speed and reducing overshoot.
Inertia matching is mainly based on the following 5 reasons:

1. System stability
Inertia mismatch may cause resonance in the system, which can seriously affect the stability of the system.
For example, if the load inertia does not match the motor inertia, when the motor accelerates or decelerates, vibration will occur near a certain speed or acceleration, causing the system to malfunction.

2. Control accuracy
Inertia matching can reduce the error of motor position control.
For example, when the motor drives the load to start or stop quickly, if the inertia does not match, the control algorithm of the motor will be unable to accurately track the given position command, resulting in position errors.

3. Response speed and overshoot
Inertia matching can improve the response speed of the system and reduce overshoot.
If the load inertia is greater than the motor inertia, the response speed of the system will slow down, leading to an increase in overshoot.
On the contrary, if the load inertia is less than the motor inertia, the system will start oscillating before reaching the set position.

4. Energy efficiency
Inertia matching also helps to improve the energy efficiency of the system.
When the load inertia matches the motor inertia, the motor can more efficiently convert electrical energy into mechanical energy, reducing energy waste.

5. Protecting the motor
Excessive load inertia may cause motor overload and damage.
By appropriate inertia matching, the motor can be protected from overload damage.