Hello, Gaurav!

It seems like the error occurs under fixed-step type of solver (see the attach.#1). Change the type from fixed-step to variable-step and choose some solver (see attach#2). I guess it would be much preferable to select one of "ode23" solvers. At least, it helped me before. If it doesn't work, try to reduce max step size or change any tolerance.

I hope it helps. Best wishes!

you should check your model a gain and if every thing is correct then change the step size, solver type, use variable step solver and change the error tolerance

Thanks Alexander Pugachev sir and Mohamed Abdelrahem sir  for your valuable reply.

I made the changes whatever both of you told me but getting the same error,also checked the simulation........I keep the max step size as 0.2 for ode23 as per your advice but still getting the same error. Now i am using the Dormand-Prince solver but having same error.

if you use division in your model add saturation block, may be it divided by zero.

Yes, as it said by Mohamed Abdelrahem, you could restrain denominator of your function coming to the block of division for the purpose of avoiding division by zero. Also, try to use the next settings in Configuration parameters (picture#2 from my previous answer) for variable-step: Algorithm -> Adaptive (default setting is non-adaptive), zero-crossing control->enable all (default one is use local settings).

Regards.

I made all the changes that you and Mohamed Abdelrahem  sir told me but getting the same error. That error is related to division block which I used. I attached designe of another control which is having the error as follows:

Error in port widths or dimensions. Output port 1 of 'strial3/powergui/EquivalentModel1/Gates/From3' has 3 elements. This port does not accept the dimensions (or orientation) specified by the output signal.

Please also see the bellow attchment

try to follow the error message to find where is the fault. Normally this happens when you use Mux or Demux block