When I am adding a very small value resistance in series with a inverter switch of one leg, then that phase current is reversed by 180 degree.

In DTC of IM model(DTC_SV_2013a.slx), when i am adding a resistance in series with a inverter switch of one leg, then that phase current is reversed by 180 degree. why? or what is the fault ? Whatever value of resistance you can put may be very low or may be high. Please help me giving your valuable suggestion.

Answer 1

[Joel Van Sickel]

Hello Jayanta,

this issue has to do with this model's initial conditions. You can see from the graph that at first, there is current flowing through the converter, but it isn't controlled or three phase. This means the model is not starting in a stable state, and current starts flowing immediately. Slightly changing the resistance changes the path this current will flow through the model in this arbitrary state. You will see that a small resistance has a very little impact on the model once the system is being controlled, but a large resistance will have a very large effect on it when being controlled. This is mostly just due to the fact that this model is not starting in a truly 'off' state. Further questions could be directed to the author of this model and why they made certain decisions.

Regards,

Joel

[JAYANTA DIGAR]

Thank You Sir.