Hello,

In the control unit CU240E-2, is there a parameter with Siemens expert filter that does posible reading Current THD harmonics?

If the parameter exists, what is the parameter?

I have un PM240-2, MLFB: 6SL3210-1PE33-7CL0 with CU240E-2 and BOP-2.

Best regards,
Joel Nuñez​

Hi,

for SINAMICS I would not know of any parameter that shows the THD values. 

Hi,

even if you would have this THD measurment of current, how would you relate it to disturbances or whatever?

Sure it is mostly generated by the drive itself with voltage PWM generation and partially smoothed out by inductances after the drive.

I am not aware of any parameter which shows harmonic levels, in the drive specification there are predicted levels which will bear little relationship to actual values found on site. Whilst it is possible to attenuate these levels with inductors, and active filtering, realistic harmonic values are created by the site conditions, and must be understood, measured, and tabulated.

It is the site conditions which are required for any estimate of harmonic values. Pre, and post installation levels from site must be obtained; essential in order to protect the design form complaint post installation.

SIZER, provides a good prediction for harmonic levels, if site values are available, Voltage, impedance, and fault levels are typical measurements required for this calculation. This will protect the design specification from inadequate supplies, and over optimistic expectations from pre contract deals.

Tractor