Is it possible to run the power_wind_dfig model with ZERO speed?

I want to run the power_wind_dfig model starting at zero speed. The problem is that when I try so, the speed goes to -0.2 pu and the results don't make sense. Even with increasing wind speed, I cannot make the machine speed positive.

Answer 1

[Christine Li]

Hi Sahand,

Can you share how did you configure the model to start from 0 speed?

For this shipping example, the initial condition is defined by a .mat file. And the model has defined a InitFcn callback to load the inital values, where the inital motor speed is defined 0.993pu. Everytime when you hit run, it will load this .mat file.

One way to change the inital motor speed is to define the xInitial in 'PreLoadFcn' callback, and modify the inital motor speed to 0 by run this in the commond before run the model:

>> xInitial.signals(44).values = 0;

Here is the simulation result of motor speed with 0 inital:

Hope this is helpful!

Best,

Christine

[Sahand Liasi]

Hi,

You need to run the model till the time that the speed is zero. Then, save that state. For saving, you can use the following steps.

If you modify this model, or change parameter values of power components, the initial conditions stored in the "xInitial" variable will no longer be valid and Simulink® will issue an error message. To regenerate the initial conditions for your modified model, follow the steps listed below:

1. In the Configuration Parameters pane, check "Final States" parameter.

2. Start simulation. When Simulation is completed, verify that steady state has been reached by looking at waveforms displayed on the scopes. The final states which have been saved in the "xFinal" array can be used as initial states for future simulations. Executing the next two commands copies these final conditions in "xInitial" and saves this variable in a new file (myModel_init.mat).

>> xInitial=xFinal;

>> save myModel_init xInitial

3. In the InitFcn window of Model Properties pane, replace the line "xInitial = init_power_wind_dfig;" with "load myModel_init.mat". Next time you open this model, the variable xInitial saved in the myModel_init.mat file will be loaded in your workspace.

4. In the Configuration Parameters pane, check "Initial state".

5. Start simulation and verify that your model starts in steady-state.

6. Save your model.

[Christine Li]

Hi Liasi,

Can you elaborate more about "The problem is that when I try so, the speed goes to -0.2 pu and the results don't make sense. "? and would you be able to start from zero speed, if not, what error message did you get?

Thanks,

Christine