In wind turbine with induction generator system, I keep getting NAN EM torque. How to fix this?

I am trying to simulate an induction generator-based wind turbine system connected to an infinite bus through 2 transmission lines. I am using double squirrel cage generator and the input is the speed in perunit. I compute the speed using a small block for the swing equation Tem-Tm=Jdw/dt (and Wm=Wg) but for now I am fizing it to 1.09. The EM torque from the generator gives me NAN no matter what I change. Does anyone know how to fix this issue?

Answer 1

[Peter O]

So you're generating, fixing the rotor speed of the machine to 1.09 per unit and supplying the machine from an infinite 3-phase bus (leaving just torque and currents as unknowns), but the output you're getting back is NaN? What are the parameters of the machine? To confirm, the infinite bus is running at 1.0 PU, with its frequency set to 1.0?

[Bayan Hussein]

Hello Peter O. First, I would like to thank you so much for your answer. What I'm trying to do is simulate a wind-turbine with a double squirrel cage generator. I am supposed to work with the speed rather than the mechanical torque. Thus, I am using the swing equation to generate this speed in a loop-kind-of block. However, right now I am facing the issue of the NaN EM torque so the speed itself is not being calculated. I tried to fix it to 1.09 to see what is the issue but I still get the same NaN problem.

The machine parameters are as follows

I am supposed to work with an infinite bus so I added the 3ph source to emulate that. However, I kept at as swing because I dont know what to set it as. Is its voltage and frequency to 1.0 pu with these parameters?