Bakez
Member level 1
I have a PI controller controlling the sinusoidal current through an inductive load of a single phase DC-AC inverter. When I simulate a low frequency sine wave the controller gives the correct RMS values just fine, however when I increase the required frequency to 50Hz (like what is needed on the grid) the controller becomes inadequate and the RMS current through the load is much lower than the reference current. I think it is something to do with the fact there is phase displacement at 50Hz. The bode plot is attached.
As you can see at 50Hz there appears to be about 20 degrees displacement at 50Hz while very little at lower frequencies. I think that this is the problem as the output sine wave is lagging significantly behind the input and therefore the error being calculated is wrong. If I am correct in this assumption then what can I do to fix this? Or is there likely to be another reason?
As you can see at 50Hz there appears to be about 20 degrees displacement at 50Hz while very little at lower frequencies. I think that this is the problem as the output sine wave is lagging significantly behind the input and therefore the error being calculated is wrong. If I am correct in this assumption then what can I do to fix this? Or is there likely to be another reason?
