Harmonic filter in simulink

Good day everyone, i am having some problems with a simulink project for school, i created a single phase harmonic filter and got it working, however when trying to apply it to a three phase system it isn't working. For my project i have to simulate harmonics of the 3rd 5th and 7th harmonic and together with the first harmonic they are all used as current sources to act as a non linear load and inject harmonics into the system. With the 3 phase system however i am unable to generate the harmonics since the current waveform stays sinusoidal. Any help would be greatly appreciated. Thank u