Variable frequency drive parameters setting (1)

Lots of parameters need to be set in the variable frequency drive, and each parameter has a setting range, improper setting in individual parameter will result in the variable frequency AC drive can not work smoothly. Therefore, every parameter must have a correct setting to ensure the whole system operation security.

1. Control modes:

Such as speed control, torque control, PID control, etc. Generally we need to identify static or dynamic according to control accuracy after confirm the control mode.

2. Minimum operating frequency:

It means the electric motor minimum running speed. The cooling performance is very poor when the motor is running at low speed, if the motor runs at low speed for a long time, it will cause the motor burned. And in low speeds, the current in the cable also will goes up which will lead to cable heating.

3. Maximum operating frequency:

Normally the AC drive maximum frequency is up to 60Hz, and few variable frequency drives even up to 400 Hz. The high frequency will make the motor runs in high speed, for general motors, the bearing can not be operated in over rated speed for a long time, the motor rotor is able to withstand such centrifugal force or not.

4. Carrier frequency:

The higher carrier frequency is set, the larger harmonic components caused, it’s closed related to cable length, motor heating, cable heating, variable frequency AC drive heating and other factors.

5. Electric motor parameters:

Setting the motor power, current, voltage, speed, maximum frequency in the variable frequency drive, these parameters can be obtained from the motor nameplate directly.

6. Frequency hopping:

The resonance phenomenon may occur at a frequency point, especially when the whole system is in relative high value; It needs to concern to avoid compressor surge point in controlling the compressor.