Why do I receive an error message related to inconsistent dynamic states while running a model using SimHydraulics 1.5 (R2009a)?

I am designing a model of a hydraulic to hydraulic booster by connecting two dual-acting hydraulic cylinders together. Irrespective of the values or components that I add in between them, it does not work. I receive the following error message :

Dynamic states at start of simulation are not consistent. Setting all dynamic state initial conditions to zero may fix this problem.

Answer 1

[MathWorks Support Team]

This is an expected behavior while building models in SimHydraulics 1.5 (R2009a).

Run the attached 'Accumulatorexpand_withbooster_simple.mdl' to generate the error message. The error is caused by the different initial condition settings between the Gas charged Accumulator and the Cylinder (Refer to connection at 'Big Piston Left Port2' ). The stock model of a Cylinder is built with zero pressure initial condition, while there is some initial pressure set in the Gas charged Accumulator.

These two different pressures stopped the simulation due to which the error message was generated. Adding a fixed area Orifice between these components resolves the issue allows for the difference in pressure and the model now simulates. Run the attached 'Accumulatorexpand_withbooster_fixed.mdl' for the same.

[Sriram Narayanan]

The attachments have been updated. Download the model "Accumulatorexpand_withbooster_fixed.mdl" that resolves the issue.