Circuit Breaker in open position will create RMS block error.

In fact there is similar problem in simpowersystems. when you put circuit breaker in your model with external control and when set the breaker off(zero to open)simulation will stop with same error.however it work when CB is in on position. "Derivative input 1 of 'New_loads/RMS1/integ' at time 1.0E-5 is Inf or NaN. Stopping simulation. There may be a singularity in the solution. If not, try reducing the step size (either by reducing the fixed step size or by tightening the error tolerances)"

Answer 1

[Sabin]

Check this similar question:

https://www.mathworks.com/matlabcentral/answers/99084-why-am-i-receiving-error-messages-about-singularities-in-my-simulink-model

You can also go directly to this blog post for more tips:

https://blogs.mathworks.com/simulink/2024/07/22/derivative-of-state-1-in-block-x-y-integrator-at-time-0-55-is-not-finite/