How to fix this issue while trying to simulate a PV Panel composed of PV Cells (represented as 36 diodes in series into de subsystem)

I tried to simulate a PV panel (with 36 diodes in series in subsystem) but it doesnt converge into a solution, and I get the following warning, how do I solve it? when I simulate PV Panel with one diode the simulation is ok.

[Walter Roberson]

The complete messages are:

The model may not give enough information to make it possible to solve for values of some of its variables. Specific advice is given below. all components and nodal across variables involvedCannot solve for one or more variables: 'Subsystem.Diode1.private.Diode.v_diode' (Intrinsic diode voltage) 'Subsystem.Diode2.private.Diode.p.v' (Voltage)

Component:Simulink | Category:Model warning

An error occurred during simulation and the simulation was terminated

Caused by:

• ['PV_Panel/Solver Configuration']: Transient initialization at time 8.900295434028806e-308, solving for consistent states and modes, failed to converge.
• Nonlinear solver: Linear Algebra error. Failed to solve using iteration matrix.
• The model may not give enough information to make it possible to solve for values of some of its variables. Specific advice is given below. all components and nodal across variables involvedCannot solve for one or more variables: 'Subsystem.Diode10.n.v' (Voltage) 'Subsystem.Diode10.ni.v' (Voltage) 'Subsystem.Diode10.power_dissipated' (power_dissipated) 'Subsystem.Diode10.private.Diode.n.v' (Voltage) 'Subsystem.Diode10.private.Diode.v_diode' (Intrinsic diode voltage) 'Subsystem.Diode10.v' (Voltage) 'Subsystem.Diode10.v_diode' (Intrinsic diode voltage) 'Subsystem.Diode11.n.v' (Voltage) 'Subsystem.Diode11.ni.v' (Voltage) 'Subsystem.Diode11.p.v' (Voltage) 'Subsystem.Diode11.private.Diode.n.v' (Voltage) 'Subsystem.Diode11.private.Diode.p.v' (Voltage) 'Subsystem.Diode11.private.ohmicResistance.n.v' (Voltage) 'Subsystem.Diode11.private.ohmicResistance.p.v' (Voltage) 'Subsystem.Diode11.private.pi.v' (Voltage) 'Subsystem.Diode12.n.v' (Voltage) 'Subsystem.Diode12.ni.v' (Voltage) 'Subsystem.Diode12.p.v' (Voltage) 'Subsystem.Diode12.private.Diode.n.v' (Voltage) 'Subsystem.Diode12.private.Diode.p.v' (Voltage) 'Subsystem.Diode12.private.ohmicResistance.n.v' (Voltage) 'Subsystem.Diode12.private.ohmicResistance.p.v' (Voltage) 'Subsystem.Diode12.private.pi.v' (Voltage) 'Subsystem.Diode13.n.v' (Voltage) 'Subsystem.Diode13.ni.v' (Voltage) 'Subsystem.Diode13.p.v' (Voltage) 'Subsystem.Diode13.private.Diode.n.v' (Voltage) 'Subsystem.Diode13.private.Diode.p.v' (Voltage) 'Subsystem.Diode13.private.ohmicResistance.n.v' (Voltage) 'Subsystem.Diode13.private.ohmicResistance.p.v' (Voltage) 'Subsystem.Diode13.private.pi.v' (Voltage) 'Subsystem.Diode14.n.v' (Voltage) 'Subsystem.Diode14.ni.v' (Voltage) 'Subsystem.Diode14.p.v' (Voltage) 'Subsystem.Diode14.private.Diode.n.v' (Voltage) 'Subsystem.Diode14.private.Diode.p.v' (Voltage) 'Subsystem.Diode14.private.ohmicResistance.n.v' (Voltage) 'Subsystem.Diode14.private.ohmicResistance.p.v' (Voltage) 'Subsystem.Diode14.private.pi.v' (Voltage) 'Subsystem.Diode15.n.v' (Voltage) 'Subsystem.Diode15.ni.v' (Voltage) 'Subsystem.Diode15.p.v' (Voltage) 'Subsystem.Diode15.private.Diode.n.v' (Voltage) 'Subsystem.Diode15.private.Diode.p.v' (Voltage) 'Subsystem.Diode15.private.ohmicResistance.n.v' (Voltage) 'Subsystem.Diode15.private.ohmicResistance.p.v' (Voltage) 'Subsystem.Diode15.private.pi.v' (Voltage) 'Subsystem.Diode16.n.v' (Voltage) 'Subsystem.Diode16.ni.v' (Voltage) 'Subsystem.Diode16.p.v' (Voltage) 'Subsystem.Diode16.private.Diode.n.v' (Voltage) 'Subsystem.Diode16.private.Diode.p.v' (Voltage) 'Subsystem.Diode16.private.ohmicResistance.n.v' (Voltage) 'Subsystem.Diode16.private.ohmicResistance.p.v' (Voltage) 'Subsystem.Diode16.private.pi.v' (Voltage) 'Subsystem.Diode17.n.v' (Voltage) 'Subsystem.Diode17.ni.v' (Voltage) 'Subsystem.Diode17.p.v' (Voltage) 'Subsystem.Diode17.private.Diode.n.v' (Voltage) 'Subsystem.Diode17.private.Diode.p.v' (Voltage) 'Subsystem.Diode17.private.ohmicResistance.n.v' (Voltage) 'Subsystem.Diode17.private.ohmicResistance.p.v' (Voltage) 'Subsystem.Diode17.private.pi.v' (Voltage) 'Subsystem.Diode18.n.v' (Voltage) 'Subsystem.Diode18.ni.v' (Voltage) 'Subsystem.Diode18.p.v' (Voltage) 'Subsystem.Diode18.private.Diode.n.v' (Voltage) <a href="matlab:simscape.internal... (Truncated error message at maximum length of buffer.)

Answer 1

[Sivsankar]

Hi Raul,

Since you have not shared the file, I’ve limited knowledge on your model. But I believe that the error message indicates that there is an issue with the execution time setting for the XY Graph block. I think it may be due to algebraic loop constraints.

One possible workaround is to break any algebraic loops present. You can check if any algebraic loop is present through the ‘getAlgebraicLoops’ command and break any loops if present. Please leverage the following documentation to understand the usage of the function:

https://www.mathworks.com/help/simulink/slref/simulink.blockdiagram.getalgebraicloops.html

Another possible workaround is to tighten the relative tolerance as stated by the diagnostic viewer. You can change it in the solver settings. You could also try to use stiff solvers such as ode15s as its more suitable for real-time systems.

These are some troubleshooting techniques that you can apply on your model. I hope it may rectify the issue. If the issue persists, please share the model here, so that I can get more details.

Thanks

[Raúl]

Hi Sivsankar:

I attach the model. I will try your suggestions. Sorry for my delayed reply.

Thanks

Regards

R.P.