Impedance Calculator of powergui block of a three-phase filter not displaying expected results

I am not getting the expected results of Impedance Calculator function of the powergui block. I am trying to measure the frequency response of a 13th harmonic filter. The resonance frequency is 780 Hz; therefore, I would expect the imedance the lowest at 780 Hz. The powergui impedance calculator does not reflect this result.

I set the Inductance and Capacitance values to a resonance frequency of 780 Hz.

Since the filter is tuned to the 13 harmonic (780 Hz), I would expect the impedance to the lowest value at 780 Hz like I drew in the red.

Answer 1

[Satwik]

Hi,

To my understanding, you want to measure the frequency response of a 13th harmonic filter and are getting incorrect results. It appears to me that the ‘impedance calculator’ for the ‘powergui’ block does indeed give the expected result, with the impedance value being the lowest at 780 Hz for the 13th harmonic, as shown in the image below.

Here is a screenshot of the model I used, which produced the above result. The values of inductance and capacitance are set to match yours.

If you are not seeing this result, there may be discrepancies due to incorrect blocks or connections in the model.

You may refer to the example ‘three-phase harmonic filter’ model provided in the documentation below to ensure that your setup is correct:

https://www.mathworks.com/help/sps/ug/three-phase-harmonic-filters.html

For more information on three-phase harmonic filters you may refer to the below documentation:

https://www.mathworks.com/help/sps/powersys/ref/threephaseharmonicfilter.html

Feel free to share your model to help debug if the issue persists.