Low Pass Active filter for harmonic mitigation in three phase system.

Hi There, I am currently struggling to connect a simple low pass filter to allow 3rd and 5th harmonics through as a hybrid filter theory. My Experience in Matlab is minimal and struggling to connect the Low Pass Filter to the three phase source and load?

Is there specific blocks required for this to work? I Have attached a IMG of what I am referring to.

Thanks,

[Shivam Gothi]

Hello @Cornelus,

The image is not attached. Could you please share it ?

And second thing, are you trying to mitigate 3rd and 5th harmonic, or you want to allow them to pass ?

Answer 1

[Vinay]

Hi @James,

Harmonics can be effectively removed using low-pass filters (LPF). While 'L' filters, which are first-order low-pass filters, can attenuate harmonics, they require large inductance values and are not ideal for this purpose.

Instead, an 'LCL' filter, which functions as a third-order low-pass filter, can be utilized to filter harmonics from the system. The design specifications for LCL filters can be modelled as follows:

Cutoff frequency =

Where

The Simulink model for the LCL filter is attached below.

Kindly refer to the below documentation of tuning the “LCL filter” parameter for more details:

https://www.mathworks.com/matlabcentral/fileexchange/53377-lcl-filter-design-inlcuding-the-current-control-tuning

I hope this helps!