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dynawo / dynawo

This repository contains Dynaωo's simulation tool code.
http://dynawo.org
Mozilla Public License 2.0
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Derivative MSL block vs der operator #2765

Closed ErwanGuichard49 closed 1 year ago

ErwanGuichard49 commented 1 year ago

On GitLab branch 521_add_inelfe, the model _dynaworte/dynawo/sources/Models/Modelica/DynawoRTE/Electrical/DC/Specific/Inelfe/BaseControls/DcSiem.mo prevents the simulation dynawo-rte/nrt/data/HVDC/Inelfe/HVDC.jobs from being run.

Using the operator der yields at the beginning of the simulation the following error

the number of algebraic/differential variables is different from the number of algebraic/differential equations in the simulated problem

If the equations using der are replaced by the MSL Derivative block, the simulation runs smoothly, even if the operator der is used in other equations.

To reproduce the issue, in DcSiem.mo, uncomment lines 64 and 65, comment lines 51, 52 and 66 to 69.

rosiereflo commented 1 year ago

The error message is correct: with the original equations, this models contains 3 derivative variables for 5 differential equations whereas Dynawo makes the assumption that the system is squared for algebraic and differential variables/equations. using the Modelica.Blocks.Continuous.Derivative simply adds 2 differential equations, solving this issue. Another possibility is to use 2 intermediate algebraic variables Real der = der(var1).

ErwanGuichard49 commented 1 year ago

Addng two algebraic variables derIDci = der(IDci) (i = 1 or 2) enables the simulation to run smoothly.