Important factors for replacing servo control system
In many cases, we need to replace the solution with servo products, such as replacing the existing motor with a new servo motor.
Reasons may include: product scrap, cost savings, delivery time or technology upgrade.
When it comes to the specific context of each application, many important factors may need to be considered. 1.
Healthy motivation, no matter why you need to replace servo products, you must understand and always keep in mind the top priority: reducing risks.
Good replacement procedures can minimize the possibility encountered during the upgrade process. Potential problems.
If the potential risks in the replacement process are not carefully managed, the possibility of system failure will be increased.
Therefore, cost is not a decisive factor in the replacement procedure!
A good alternative solution can not only minimize risks, but also reduce system costs, rather than reduce costs, but accept higher potential risks. 2.
The stability of the axis and inertia matching are very important, but they are often ignored.
The servo motor used for replacement shall have the same rotor inertia as the original servo motor, or be as similar as possible.
The goal is to maintain system stability after installing a new server.
Of course, the assumption here is that the original system has achieved the required stability. If you want to replace a lower resolution system (
For example, tachometer, reversible encoder or old-fashioned, Resolver type system)
, Usually should use a resolution of not less than 220 lines per revolution (CPR)The high-resolution sinusoidal encoder feedback device based on.
Flexibility can be increased by matching rotor inertia.
In general, when high-resolution equipment is used to improve the resolution of feedback equipment, the inertia of the replacement servo must be at least 1/3 of that of the original motor. Of course, it is best to reach half.
This method has been successfully used in many application fields. 3.
Speed and torque speed and torque matching are equally important.
The performance of the replacement motor shall reach or exceed the performance of the original motor. Analyze two catalog parameter values (Namely continuous torque, rated speed)It is very important to ensure that there are no defects.
The torque value must also be compared within the speed range of each motor.
Comparing graphs is very useful by comparing motor speed/torque curves and manually drawing the required values in a spreadsheet.
For example, draw the continuous torque at 1000 PRM, motor A = X Nm, motor B = Y Nm, and perform the same operation over the entire speed range. 4.
Motor size, although size is not particularly important for motor performance, during the replacement process, if a new servo motor is installed at the same size as the original motor, it will help to achieve flow.
The outline drawings of the two motors should be analyzed to ensure consistency. Even if the industry standard basis (Such as NEMA or ICE)The motor is also a good method.
Relevant standards usually stipulate that the guide sizes of adapters and Bolt rings are the same, but the shaft sizes are usually not fixed.
For example, although you want to replace the NEMA 34 motor, the product definition of each manufacturer may vary greatly!
5. Other factors, is the motor the only part in the machine that needs to be replaced?
Usually, replacing the server means replacing the drive, cable and, in some cases, even the controller.
In this case, if the manufacturer's suggestion is followed, the difference in motor windings can be taken as a secondary consideration.
However, if the replaced motor will be used with the original driver, it should be carefully checked. For example, for winding data (Including motor constants: Kt and Ke)
The type and resolution of the feedback device, as well as the pin layout of the cable, must be carefully checked and matched.
In addition, different servo motor manufacturers usually use different units and conversion methods for these key parameters.
In the comparison process, it may be difficult to clearly distinguish the definition and unit of the motor.
This article provides some useful supplementary information in this respect and introduces some common precautions in the servo replacement process.
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