why does my modified 100kw grid-connected PV system not work?

Hi, I am working on a 100kw grid-connected PV system that was preloaded in the Matlab toolbox. the model has 66 parallel modules and 5 series modules in its PV array block. I just tried to modify this PV array as two strings of 5 series modules and a 64 P, 5 S array as shown, but the model didn't give any output, I don't know why? I attached the original and modified simulink files to let you run the two models for illustrating the problem...I expect your help, please.

Answer 1

[Joel Van Sickel]

Unfortunately, for fast simulations, that solar panel block was not designed to be placed in series with itself. If you really need to, you can, but it will greatly slow your simulation down. You can change the block to a robust model (an option in the solar panel mask). This will disable modelling a varying temperature but allow for a nonlinear iteration to improve simulation accuracy (and prevent the nan result). After that, you have to go to the powergui block and change the advanced settings for nonlinear solvers. I found that I needed to reduce the tolerance, and greatly increase the number of iterations to get it to work. I was experimenting with only 2 solar panels in series. I used 1e-6 tolerance and 100 nonlinear iterations. Making the time step smaller will also help. However, all of this will drastically reduce the speed of your simulation. I recommend using the single block, and specying number of panels in series and parallel instead of explicitly modelling them unless absolutely necessary.

[Haider Abbas]

Thanks for your reply, it was very helpful and the model just works well, but as you mentioned the simulation time is too long and this is a big problem for me because I plan to run this model a dozen times with different input variables .thanks again for the help

[Joel Van Sickel]

If that is the case, you should use a single solar panel block and specify the number in series and parallel instead of modelling each of them seperately.

[Haider Abbas]

No, I can't because my work requires me to deal with each module of the array separately

[Joel Van Sickel]

You can try to simplify the utility model and remove the converters (maybe replace them with average converters) or you can try to redo the model using simscape core components (the blue components) where putting solar cells in series shouldn't slow things down as much.

Answer 2

[Pankaj Negi]

Hi, Joel , i also working on this default system and need to use LCL filter to remove the harmonics , but when i am using LCL filter the grid side power is showing negative.

can you please help me in this matter , why is showing negative while using LCL filter insted of L filter .