Simulation of a Piezoelectric Stack

I am a beginner in Simulink and I need to check the output power and voltage for the supplied voltage of a Piezoelectric stack for a project. So if anybody could help me out with a basic circuit with all the componets required because the circuit that I made gives this error: Dependency found among topology equations. Check for missing reference node.

Thank you

[John D'Errico]

It would be far easier if you provide what you did. It is easier to help fix something than to try to tell you what you might have done wrong.

[Pankhi Kapil]

This is the basic circuit that I designed, inputs are yet to be set