Characteristic setting for a permanently excited synchronous motor (PSM). A synchronous motor by design has lower loss than an ASM ( because permanent magnets replace the magnetizing current). It is normally not internally cooled, but discharges its heat loss by internal convection. For that reason it has a different characteristic to an asynchronous motor. It is necessary to adapt the I2xt characteristic because the factory setting mostly does not exactly map the present motor. The difference between factory setting and the characteristic configured above is shown in the following illustration.
If the I2xt type is set to "THERM(1) = Thermal time constant dependent", all settings apart from the thermal time constant are disabled.
Bild: PSM characteristic
Frequency/current values
|
Frequency |
Motor current |
|---|---|
| f0 = 0 Hz | I0 = 133.33 % of IN |
| f1 = 250 Hz | I1 = 100% of IN |
| fN = 250 Hz | IN = 100% |
Tabelle: PSM characteristic
Typical setting for the permanently excited synchronous machine
If the integrator exceeds its limit value, the error E-09-01 is triggered. The current value of the integrator is indicated in parameter P 0701(0) Mon_ActValues.
Bild: PSM characteristic factory setting
Calculation of capacity utilization via exponential function with thermal time constant of motor:
Setting of I2t type:
Copyright © LTi DRiVES GmbH, Januar 2013, ID-Nr.: 0842.26B.1-00 DE