When is it necessary to consider increasing the capacity of the frequency converter
Time:2023-05-20
Views:137
Everyone knows that when using a frequency converter, the motor cannot be too far away from the frequency converter equipment, and it needs to be used at a certain distance to operate normally. If the capacity of the frequency converter is too large, it is easy to cause voltage distortion in the local power supply system. So under what circumstances should we consider increasing the capacity of the frequency converter?
1. The rated current of the frequency converter is too low
As mentioned above, when the rated current of some frequency converters is less than that of motors of the same capacity, a frequency converter with a higher gear should be selected based on the load situation of the motor.
2. Motor may be overloaded for a short period of time
Because the so-called "short time" of an electric motor is relative to the heating time constant. Less than a few minutes, more than a few tens of minutes. The overload capacity of the frequency converter is usually 150% for 1 minute. Compared to an electric motor, it has no overload capacity. So, if the motor may overload during the think tank time, the capacity of the frequency converter should be increased.
3. Those with special requirements for acceleration and deceleration time
The acceleration time of an electric motor is a relative concept related to the magnitude of inertia. For example, an acceleration time of 5 seconds may be too short compared to loads with large inertia (GD2); But compared to loads with small inertia (GD2), it may be too long.
Generally speaking, for loads that require starting and stopping under heavy loads, increasing the capacity of the frequency converter should be considered in the following situations:
(1) Those who are required to be able to start and stop quickly;
(2) Those who jog frequently.
4. Those with impact loads
For example, the electric motor is combined with the load through a clutch. Usually, when the motor has already rotated, the load also rotates due to the combination of the clutch. Obviously, at the moment when the clutch is just engaged, the speed of the motor will decrease, the slip will increase, and the current will also increase, which may cause overcurrent protection action. In response to this situation, the capacity of the frequency converter should be increased.