OpenModelica trivial mechanical system structurally singular - simulation

While trying to model a more complex mechanical system in OM, I got the following error:
Internal error IndexReduction.pantelidesIndexReduction failed! System is structurally singular and cannot be handled because the number of unassigned equations is larger than the number of states.
So I reduced the system to a more or less trivial one, but still got the same error.
The intention of this trivial example is to basically model the fixation of a bridge on both sides, where you have one rotational joint and one sliding/rotational joint, thereby making this multibody system determinate in the planar case (rotational joints are around z). To account for the system being overdetermined out-of-plane, I'd replace the prismatic joint by a cylindrical one, but that doesn't seem to make a difference.
Replacing the right revolute-joint + prismatic joint by a spring works, but that's obviously a different case and doesn't make me understand the error of the described model.
Any ideas?
The model code is like this:
model structsingtst01
inner Modelica.Mechanics.MultiBody.World world annotation(
Placement(visible = true, transformation(origin = {-76, 66}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Mechanics.MultiBody.Joints.Revolute revolute(phi(displayUnit = "rad"), stateSelect = StateSelect.avoid) annotation(
Placement(visible = true, transformation(origin = {-44, 36}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Mechanics.MultiBody.Parts.Fixed fixed(r = {-1, 0, 0}) annotation(
Placement(visible = true, transformation(origin = {-76, 36}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Mechanics.MultiBody.Parts.Fixed fixed1(r = {1.2, 0, 0}) annotation(
Placement(visible = true, transformation(origin = {116, 36}, extent = {{10, -10}, {-10, 10}}, rotation = 0)));
Modelica.Mechanics.MultiBody.Parts.BodyBox bodyBox(enforceStates = true, r = {1, -1, 0}) annotation(
Placement(visible = true, transformation(origin = {-14, 36}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Mechanics.MultiBody.Parts.BodyBox bodyBox1(enforceStates = true, r = {1, 1, 0}) annotation(
Placement(visible = true, transformation(origin = {26, 36}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Mechanics.MultiBody.Joints.Revolute revolute1 annotation(
Placement(visible = true, transformation(origin = {56, 36}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Mechanics.MultiBody.Joints.Prismatic prismatic(n = {1, 0, 0}, s(fixed = true, start = 0.2), useAxisFlange = false) annotation(
Placement(visible = true, transformation(origin = {86, 36}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
equation
connect(fixed.frame_b, revolute.frame_a) annotation(
Line(points = {{-66, 36}, {-54, 36}, {-54, 36}, {-54, 36}}));
connect(revolute.frame_b, bodyBox.frame_a) annotation(
Line(points = {{-34, 36}, {-24, 36}, {-24, 36}, {-24, 36}}, color = {95, 95, 95}));
connect(bodyBox.frame_b, bodyBox1.frame_a) annotation(
Line(points = {{-4, 36}, {16, 36}}, color = {95, 95, 95}));
connect(revolute1.frame_a, bodyBox1.frame_b) annotation(
Line(points = {{46, 36}, {36, 36}}, color = {95, 95, 95}));
connect(revolute1.frame_b, prismatic.frame_a) annotation(
Line(points = {{66, 36}, {76, 36}}, color = {95, 95, 95}));
connect(prismatic.frame_b, fixed1.frame_b) annotation(
Line(points = {{96, 36}, {106, 36}}, color = {95, 95, 95}));
annotation(
uses(Modelica(version = "3.2.3")),
Diagram(coordinateSystem(extent = {{-200, 0}, {200, 0}})),
Icon(coordinateSystem(extent = {{-200, 0}, {200, 0}})),
version = "");
end structsingtst01;

Actually this is similar to the "planar loop" example mentioned in the documentation for Modelica.Mechanics.MultiBody.Joints.RevolutePlanarLoopConstraint, so indeed replacing one of the Modelica.Mechanics.MultiBody.Joints.Revolute by a RevolutePlanarLoopConstraint made the model work.

Related

How can I use the SimpleGenericOrifice of the Modelica Standard Library to impose pressure loss in a pipe?

I would like to model an hydraulic network where I use the Modelica.Fluid.Fittings.SimpleGenericOrifice as a seal so I can impose the pressure loss of a pipe. Using the formula in the documentation, I can calculate the zeta coefficient of the orifice.
Here is a simplified example, here I try to impose a pressure loss of 50 bar inside my pipe1. Because the pressure should be equal at the port, I assume that it should work :
However I don't have any pressure loss in the pipe and in the orifice.
Does anyone know how to make this work ?
Here is the code of the example
model Joints_HD
replaceable package Medium=Modelica.Media.Water.StandardWater constrainedby
Modelica.Media.Interfaces.PartialMedium;
Modelica.Fluid.Pipes.StaticPipe pipe(redeclare package Medium = Medium,diameter = 0.15, length = 1) annotation(
Placement(visible = true, transformation(origin = {-38, 10}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
inner Modelica.Fluid.System system annotation(
Placement(visible = true, transformation(origin = {-70, 42}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Fluid.Sources.Boundary_pT boundary(redeclare package Medium = Medium,T = 328.15, p = 157e5, nPorts = 1) annotation(
Placement(visible = true, transformation(origin = {-66, 10}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Fluid.Sources.MassFlowSource_T boundary1(redeclare package Medium = Medium,T = 328.15, m_flow = -0.17, nPorts = 1) annotation(
Placement(visible = true, transformation(origin = {72, 10}, extent = {{10, -10}, {-10, 10}}, rotation = 0)));
Modelica.Fluid.Pipes.StaticPipe pipe2(redeclare package Medium = Medium,diameter = 0.15, length = 1) annotation(
Placement(visible = true, transformation(origin = {44, 10}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Fluid.Fittings.SimpleGenericOrifice orifice(redeclare package Medium = Medium,diameter = 0.15, dp_nominal = 5e+06, m_flow_nominal = 2.34e-9, use_zeta = false) annotation(
Placement(visible = true, transformation(origin = {2, 10}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Fluid.Pipes.StaticPipe pipe1(redeclare package Medium = Medium, diameter = 0.15, length = 1) annotation(
Placement(visible = true, transformation(origin = {2, -18}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
equation
connect(boundary.ports[1], pipe.port_a) annotation(
Line(points = {{-56, 10}, {-48, 10}}, color = {0, 127, 255}));
connect(pipe.port_b, orifice.port_a) annotation(
Line(points = {{-28, 10}, {-8, 10}}, color = {0, 127, 255}));
connect(pipe2.port_b, boundary1.ports[1]) annotation(
Line(points = {{54, 10}, {62, 10}}, color = {0, 127, 255}));
connect(orifice.port_b, pipe2.port_a) annotation(
Line(points = {{12, 10}, {34, 10}}, color = {0, 127, 255}));
connect(pipe.port_b, pipe1.port_a) annotation(
Line(points = {{-28, 10}, {-20, 10}, {-20, -18}, {-8, -18}}, color = {0, 127, 255}));
connect(pipe1.port_b, pipe2.port_a) annotation(
Line(points = {{12, -18}, {26, -18}, {26, 10}, {34, 10}}, color = {0, 127, 255}));
annotation(
uses(Modelica(version = "3.2.3")));
end Joints_HD;
Best regards,
Maxime
pipe1 has "wrong" dimensions (diameter, length, roughness etc.) since it only creates a very small pressure drop.
To verify that the rest of the model is okay — and that you can have a pressure drop of 50 bar over pipe1 at the flow set in boundary1 (0.17 kg/s) — temporarilly change pipe1.FlowModel to NominalTurbulentPipeFlow with m_flow_nominal=0.17 and dp_nominal=50 bar.
Subsequently, switch the flow model back to the default (detailed) model and adjust the pipe geometry.
By the way, you should provide a value for orifice.zeta even though it is not used.

OpenModelica: Input in second level for FMU export

I have a model, create an FMU out of it, and want to import it in to python.
Having inputs on the first canvas works, and transferring them to the blocks which are used works, too.
Because of the architecture of the python code, i need to have the prefix for the inputs as for the rest of the block.
I made a minimal example:
package testi
model source
Modelica.Electrical.Analog.Sources.SignalVoltage signalVoltage annotation(
Placement(visible = true, transformation(origin = {0, 36}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Electrical.Analog.Basic.Ground ground annotation(
Placement(visible = true, transformation(origin = {48, 22}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Electrical.Analog.Interfaces.Pin pin annotation(
Placement(visible = true, transformation(origin = {100, 0}, extent = {{-10, -10}, {10, 10}}, rotation = 0), iconTransformation(origin = {100, 0}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Blocks.Interfaces.RealInput u annotation(
Placement(visible = true, transformation(origin = {0, 108}, extent = {{-20, -20}, {20, 20}}, rotation = -90), iconTransformation(origin = {0, 108}, extent = {{-20, -20}, {20, 20}}, rotation = -90)));
equation
connect(signalVoltage.n, ground.p) annotation(
Line(points = {{10, 36}, {48, 36}, {48, 32}}, color = {0, 0, 255}));
connect(signalVoltage.p, pin) annotation(
Line(points = {{-10, 36}, {-20, 36}, {-20, 0}, {100, 0}, {100, 0}}, color = {0, 0, 255}));
connect(signalVoltage.v, u) annotation(
Line(points = {{0, 48}, {0, 48}, {0, 108}, {0, 108}}, color = {0, 0, 127}));
end source;
model base
testi.source source1 annotation(
Placement(visible = true, transformation(origin = {-42, 40}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
testi.measurement measurement1 annotation(
Placement(visible = true, transformation(origin = {44, 40}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
equation
connect(source1.pin, measurement1.pin) annotation(
Line(points = {{-32, 40}, {34, 40}}, color = {0, 0, 255}));
end base;
model measurement
Modelica.Electrical.Analog.Basic.Resistor resistor annotation(
Placement(visible = true, transformation(origin = {-24, 0}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Electrical.Analog.Interfaces.Pin pin annotation(
Placement(visible = true, transformation(origin = {-100, 0}, extent = {{-10, -10}, {10, 10}}, rotation = 0), iconTransformation(origin = {-100, 0}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Electrical.Analog.Basic.Ground ground annotation(
Placement(visible = true, transformation(origin = {30, -28}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
equation
connect(pin, resistor.p) annotation(
Line(points = {{-100, 0}, {-34, 0}}, color = {0, 0, 255}));
connect(resistor.n, ground.p) annotation(
Line(points = {{-14, 0}, {30, 0}, {30, -18}, {30, -18}}, color = {0, 0, 255}));
end measurement;
annotation(
uses(Modelica(version = "3.2.3")));
end testi;
Trying to create the FMU causes the error: Undetermined equation system: 23 equations, 24 variables, although i would provide the input "source.u" via python. If I create an additional Input directly in the base model and connect it to the input of the source, it works, but then i do not have the same prefix "source.u" in my python code, which i would really like to have.
Does anyone know a way to solve this problem?
Define a second input u inside model base and connect it to the input of source.u so you only have inputs on the top level of the FMU.
Now the FMU will happily compile and you should be able to change source.u from outside.
model base
Modelica.Blocks.Interfaces.RealInput u;
testi.source source1;
testi.measurement measurement1;
equation
connect(source1.pin, measurement1.pin);
connect(u, source1.u);
end base;

Measuring mean value with variable frequency

I want to measure the RMS value of a sine voltage with a variable frequency.
The real frequency is measured via PLL.
Problem is that the ordinary "mean" block only works with the frequency as fixed parameter, not a variable.
Is there any way to use the measured frequency as frequency for any kind of mean block, which can be used to calculate a RMS value?
Code for a basic example with standard OpenModelica blocks is attached
model var_rms
Modelica.Electrical.Analog.Basic.Ground ground annotation(
Placement(visible = true, transformation(origin = {-66, -48}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Electrical.Analog.Basic.Resistor resistor(R = 10) annotation(
Placement(visible = true, transformation(origin = {8, 50}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Electrical.Analog.Sensors.VoltageSensor voltageSensor annotation(
Placement(visible = true, transformation(origin = {8, -34}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Blocks.Math.RootMeanSquare rootMeanSquare annotation(
Placement(visible = true, transformation(origin = {58, -72}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Blocks.Sources.Step Frequency_from_PLL(offset = 50, startTime = 0.5) annotation(
Placement(visible = true, transformation(origin = {40, -28}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Electrical.Analog.Sources.SineVoltage sineVoltage(V = 230, freqHz = 50.5) annotation(
Placement(visible = true, transformation(origin = {50, 50}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
equation
connect(voltageSensor.n, resistor.n) annotation(
Line(points = {{18, -34}, {18, 50}}, color = {0, 0, 255}));
connect(voltageSensor.p, resistor.p) annotation(
Line(points = {{-2, -34}, {-2, 50}}, color = {0, 0, 255}));
connect(resistor.p, ground.p) annotation(
Line(points = {{-2, 50}, {-66, 50}, {-66, -38}, {-66, -38}}, color = {0, 0, 255}));
connect(voltageSensor.v, rootMeanSquare.u) annotation(
Line(points = {{8, -46}, {8, -72}, {46, -72}}, color = {0, 0, 127}));
connect(sineVoltage.n, ground.p) annotation(
Line(points = {{60, 50}, {76, 50}, {76, -4}, {-66, -4}, {-66, -38}, {-66, -38}}, color = {0, 0, 255}));
connect(sineVoltage.p, resistor.n) annotation(
Line(points = {{40, 50}, {18, 50}}, color = {0, 0, 255}));
annotation(
uses(Modelica(version = "3.2.3")));
end var_rms;

How do I resolve an error pertaining to a variable not located within my OpenModelica Model?

I'm currently working on building a heat recovery steam generator and have just started building from the ThermoPower Library and connected an evaporator to the economizer.
When trying to simulate, an error occurs within the OMEdit Simulator:
division by zero at time 0, (a=-458389.9207317767) / (b=0), where divisor b expression is: 8.75988806777792 * Economizer.metalTube.Am * Economizer.metalTube.rhomcm * /Real/(Economizer.metalTube.Nt)
How exactly do I trouble shoot this error if I cannot define or locate the needed variables that are causing b=0?
Please let me know what you think about this. Your time and energy is greatly appreciated.
I'm not the best at debugging my models but I have an idea and I have some confusion trouble shooting this. My initial confusion was to verify which variable resulted in b=0. However, upon inspection I noticed how the variable Economizer.metalTube.Nt, Economizer.metalTube.Am did not exist within my the economizer class. I knew it had to be rooted into my class through extensions and partial classes and tried to define these "missing" variables in the text view of my economizer model, but this simply resulted in an error saying:
[1] 11:46:14 Translation Error
[ThermoPower_HRSG_Econ_Evap: 68:3-92:112]: Variable Economizer: In modifier (Nt = 3), class or component Nt not found in .
If you have any advice and/or recommendations please leave a comment below!
///UPDATE: Moving forward after what I've learned from others and implementing their suggestions.///
After reading what you and others have said about my issue on OpenModelica I have come to a better understanding of the situation. However, I am still confused as to what is the best way to move forward to debug my model.
So my "Economizer" model, or a heat exchanger located in ThermoPower.Examples.RankineCycles.Models.HE, was having the error associated with the divisor "b=0".
When debugging, the error hyperlinked me to the package "thermal" which pointed me towards the line of code that is being flagged:
(L/Nw*Nt)*rhomcm*Am*der(Tvol) = int.Q + ext.Q "Energy balance";
This line of code is also being used in the Economizer HE class (ThermoPower.Examples.RankineCycles.Models.HE). Here in the HE.mo, the same flagged line of code from the thermal package that is causing the error is also located here. What's making my model cause the divider "b=0" are the variables: L, Nw, Nt, Am and Tvol. These variables are not defined/found in the model I am using when defining system parameters.
What's confusing for me as a OpenModelica user is that those variables just mentioned above (L, Nw, Nt, Am and Tvol) are coded/defined in the ThermoPower.Examples.RankineCycles.Models.HE text view of the component, but when I try to define/add them into my Economizer.mo belonging to the ThermoPower.Examples.RankineCycles.Models.HE class, errors are triggered claiming:
[ThermoPower_HRSG_Econ_Evap: 69:3-94:112]: Variable Economizer: In modifier
(Nt = 1), class or component Nt not found in
<ThermoPower.Examples.RankineCycle.Models.HE$Economizer>.
Essentially, the errors causing the divider "b=0" are located in the base class of the economizer I am using. However, due to the absence or in-ability to define these needed variables within my Economizer.mo model, the equation:
(L/Nw*Nt)*rhomcm*Am*der(Tvol) = int.Q + ext.Q "Energy balance";
Is now being violated. How do I fix this issue properly?
///UPDATE: CODE PROVIDED BELOW///
model ThermoPower_HRSG_Econ_Evap
ThermoPower.Gas.SourceMassFlow Source_FlueGas(
redeclare package Medium = ThermoPower.Media.FlueGas,
T = 331.59 + 273.15,
p0 = 101325,
w0 = 169.755) annotation(
Placement(visible = true, transformation(origin = {-92, 30}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
ThermoPower.Water.SourceMassFlow Source_Steam(
T = 46.45 + 273.15,
h = 203.22e3,
p0 = 80e5,
use_T = true,
w0 = 21.5) annotation(
Placement(visible = true, transformation(origin = {-10, 90}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
ThermoPower.Water.SensT sensT_WaterIn_Econ annotation(
Placement(visible = true, transformation(origin = {4, 60}, extent = {{-10,
-10}, {10, 10}}, rotation = -90)));
ThermoPower.Water.SensT sensT_WaterOut_Econ annotation(
Placement(visible = true, transformation(origin = {4, 0}, extent = {{-10,
-10}, {10, 10}}, rotation = -90)));
ThermoPower.Gas.SensT sensT_ExhaustIn_Econ(
redeclare package Medium = ThermoPower.Media.FlueGas) annotation(
Placement(visible = true, transformation(origin = {-50, 34}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
ThermoPower.Gas.SensT sensT_ExhaustOut_Econ(
redeclare package Medium = ThermoPower.Media.FlueGas) annotation(
Placement(visible = true, transformation(origin = {50, 34}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
inner ThermoPower.System system annotation(
Placement(visible = true, transformation(origin = {-90, 90}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
ThermoPower.Gas.SinkPressure Sink_FlueGas(
redeclare package Medium = ThermoPower.Media.FlueGas,
p0 = 101325) annotation(
Placement(visible = true, transformation(origin = {94, -70}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
ThermoPower.Water.SinkPressure Sink_Steam(
p0 = 80e5) annotation(
Placement(visible = true, transformation(origin = {10, -90}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
ThermoPower.Examples.HRB.Models.Evaporator Evaporator(
cm = 480,
exchSurface = 2.752,
fluidNomFlowRate = 21.5,
fluidNomPressure = 8e+06,
fluidVol = 0.01376,
gamma = 85,
gasNomFlowRate = 169.755,
gasNomPressure = 101325,
gasVol = 0.01376,
metalVol = 0.01376,
rhom(displayUnit = "kg/m3") = 8055,
rhonom_G = 1) annotation(
Placement(visible = true, transformation(origin = {0, -50}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
ThermoPower.Gas.SensT sensT_ExhaustOut_Evap(
redeclare package Medium = ThermoPower.Media.FlueGas) annotation(
Placement(visible = true, transformation(origin = {50, -66}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Blocks.Continuous.FirstOrder VoidFractionSensor annotation(
Placement(visible = true, transformation(origin = {53, -43}, extent =
{{-5, -5}, {5, 5}}, rotation = 0)));
Modelica.Blocks.Interfaces.RealOutput VoidFraction annotation(
Placement(visible = true, transformation(origin = {110, -42}, extent =
{{-10, -10}, {10, 10}}, rotation = 0), iconTransformation(origin = {110,
-42}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
ThermoPower.Examples.RankineCycle.Models.HE Economizer(
FFtype_G = ThermoPower.Choices.Flow1D.FFtypes.OpPoint,
FluidPhaseStart = ThermoPower.Choices.FluidPhase.FluidPhases.Liquid,
N_F = 6,
N_G = 6,
Tstart_G = 604.74,
Tstart_M = 573.15, counterCurrent = true,
exchSurface_F = 2.752,
exchSurface_G = 2.752,
extSurfaceTub = 5.504,
fluidNomFlowRate = 21.5,
fluidNomPressure = 8e+06,
fluidVol = 0.01376,
gamma_F = 3000,
gamma_G = 30,
gasNomFlowRate = 169.755,
gasNomPressure = 101325,
gasVol = 0.01376,
lambda = 19.8,
metalVol = 0.01376,
rhomcm = 8055 * 480,
rhonom_F(displayUnit = "kg/m3") = 997,
rhonom_G = 1) annotation(
Placement(visible = true, transformation(origin = {0, 30}, extent = {{-10,
-10}, {10, 10}}, rotation = 0)));
equation
connect(Economizer.gasOut, sensT_ExhaustOut_Econ.inlet) annotation(
Line(points = {{10, 30}, {44, 30}, {44, 30}, {44, 30}}, color = {159, 159,
223}));
connect(sensT_ExhaustIn_Econ.outlet, Economizer.gasIn) annotation(
Line(points = {{-44, 30}, {-10, 30}, {-10, 30}, {-10, 30}}, color = {159,
159, 223}));
connect(Economizer.waterOut, sensT_WaterOut_Econ.inlet) annotation(
Line(points = {{0, 20}, {0, 20}, {0, 6}, {0, 6}}, color = {0, 0, 255}));
connect(sensT_WaterIn_Econ.outlet, Economizer.waterIn) annotation(
Line(points = {{0, 54}, {0, 54}, {0, 40}, {0, 40}}, color = {0, 0, 255}));
connect(VoidFractionSensor.y, VoidFraction) annotation(
Line(points = {{58, -42}, {104, -42}, {104, -42}, {110, -42}}, color = {0,
0, 127}));
connect(Evaporator.voidFraction, VoidFractionSensor.u) annotation(
Line(points = {{10, -44}, {46, -44}, {46, -42}, {46, -42}}, color = {0, 0,
127}));
connect(sensT_ExhaustOut_Evap.outlet, Sink_FlueGas.flange) annotation(
Line(points = {{56, -70}, {70, -70}, {70, -70}, {84, -70}, {84, -70}, {84,
-70}}, color = {159, 159, 223}));
connect(Evaporator.gasOut, sensT_ExhaustOut_Evap.inlet) annotation(
Line(points = {{10, -50}, {26, -50}, {26, -70}, {44, -70}}, color = {159,
159, 223}));
connect(sensT_ExhaustOut_Econ.outlet, Evaporator.gasIn) annotation(
Line(points = {{56, 30}, {68, 30}, {68, -20}, {-50, -20}, {-50, -20},
{-70, -20}, {-70, -50}, {-10, -50}, {-10, -50}}, color = {159, 159,
223}));
connect(sensT_WaterOut_Econ.outlet, Evaporator.waterIn) annotation(
Line(points = {{0, -6}, {0, -40}}, color = {0, 0, 255}));
connect(Evaporator.waterOut, Sink_Steam.flange) annotation(
Line(points = {{0, -60}, {0, -90}}, color = {0, 0, 255}));
connect(Source_FlueGas.flange, sensT_ExhaustIn_Econ.inlet) annotation(
Line(points = {{-82, 30}, {-56, 30}}, color = {159, 159, 223}));
connect(Source_Steam.flange, sensT_WaterIn_Econ.inlet) annotation(
Line(points = {{0, 90}, {0, 66}}, color = {0, 0, 255}));
annotation(
uses(ThermoPower(version = "3.1"), Modelica(version = "3.2.3")));end
ThermoPower_HRSG_Econ_Evap;

How do I solve Modelica errors of variables, where the variables are parameters of extensions that your model is using?

I've been trying to build a Rankine Power Cycle on OpenModelica for quite some time now and have been running into a reoccurring issue that I'm just not sure how to troubleshoot.
My Issue:
I'm able to get the majority of all of my Rankine Power Cycle model iterations to at least get a checked model as well as a successful instantiation. At this point I deem my model ready to try and simulate. The types of errors that usually break my simulation are variables that are located within extended models that my model is using.
For example:
Currently I am checking and verifying sub assemblies of the Rankine Power Cycle to be able to properly verify which components work and which do not under x,y,z circumstances. My heat exchanger model is checked and is able to instantiate but upon simulation I get error codes that read:
[22] 14:34:06 Symbolic Error
[ThermoPower.Gas: 1053:5-1053:66]: Model is structurally singular, error
found sorting equations
125: 0.0 = 0.0;
for variables
HX.gasFlow.vbar[5](140), HX.gasFlow.drbdX1[2,4](125)
What the issue here for me is that the error above, or all errors of these types, are hyperlinked to either partial models or packages that my own model extends. So the variables above "vbar" or "drbdX1" are no where within my HeatExchanger Model that I built, but the components inside of my own model somehow extend to these variables that are inevitably causing the error.
Things I've tried:
I've tried adding values to the extended hyperlinked models/packages in order to fix the error. This does not do anything.
I've tried copy and pasting said lines of code into my own model in order to declare whatever package/function that has already been declared within the extension. This does not work as usually produces an error for incorrect declaration.
The hyperlinked error does little to not help on how exactly I should fix the model, or where or which model I should fix it on.
If you have any insight or recommendations on how to fix such an issue, please feel free to comment below! Thank you for your time and reading this far into my plea for help :)
Heat Exchanger Code:
model HX_Turbine_Check
ThermoPower.PowerPlants.HRSG.Components.HE HX(
FluidPhaseStart = ThermoPower.Choices.FluidPhase.FluidPhases.Steam,
N_F = 6,
N_G = 6, Tstartbar_G(displayUnit = "K") = 800,
exchSurface_F = 2000,
exchSurface_G = 1000,
extSurfaceTub = 1500,
fluidNomFlowRate = 10,
fluidNomPressure = 2e+06,
fluidVol = 5,
gasNomFlowRate = 100,
gasNomPressure = 101325,
gasVol = 10,
lambda = 20,
metalVol = 10,
pstart_F = 2e+06,
pstart_G = 101325,
rhomcm = 7900,
rhonom_F(displayUnit = "kg/m3") = 0.6,
rhonom_G(displayUnit = "kg/m3") = 0.33) annotation(
Placement(visible = true, transformation(origin = {-30, 30}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
ThermoPower.Gas.SourceMassFlow FlueGasSource(
redeclare package Medium = ThermoPower.Media.FlueGas,
T = 800,
p0 = 101325,
w0 = 100) annotation(
Placement(visible = true, transformation(origin = {-92, 30}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
ThermoPower.Gas.SinkMassFlow FlueGasSink(
redeclare package Medium = ThermoPower.Media.FlueGas,
p0 = 101325,
w0 = 100) annotation(
Placement(visible = true, transformation(origin = {32, 30}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
ThermoPower.Water.SourceMassFlow WaterSource(
T = 212.4 + 273,
h = 2799500,
p0 = 20e5,
w0 = 10) annotation(
Placement(visible = true, transformation(origin = {-30, 92}, extent =
{{-10, -10}, {10, 10}}, rotation = -90)));
ThermoPower.Water.SinkMassFlow SteamSink(
p0 = 1.01325e5,
w0 = 10) annotation(
Placement(visible = true, transformation(origin = {48, 0}, extent = {{-10,
-10}, {10, 10}}, rotation = 0)));
ThermoPower.Gas.SensT TGas_Inlet(
redeclare package Medium = ThermoPower.Media.FlueGas) annotation(
Placement(visible = true, transformation(origin = {-58, 34}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
ThermoPower.Gas.SensT TGas_Outlet(
redeclare package Medium = ThermoPower.Media.FlueGas) annotation(
Placement(visible = true, transformation(origin = {0, 34}, extent = {{-10,
-10}, {10, 10}}, rotation = 0)));
ThermoPower.Water.SensT TWater_Inlet annotation(
Placement(visible = true, transformation(origin = {-26, 60}, extent =
{{-10, -10}, {10, 10}}, rotation = -90)));
ThermoPower.Water.SensT TSteam_Outlet annotation(
Placement(visible = true, transformation(origin = {16, 4}, extent = {{-10,
-10}, {10, 10}}, rotation = 0)));
ThermoPower.Water.SteamTurbineStodola SteamTurbine(
Kt = 0.0131,
PRstart = 20,
pnom = 20e5,
wnom = 10,
wstart = 10) annotation(
Placement(visible = true, transformation(origin = {-20, -30}, extent =
{{-12, -12}, {12, 12}}, rotation = 0)));
inner ThermoPower.System system annotation(
Placement(visible = true, transformation(origin = {50, 88}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Mechanics.Rotational.Sensors.PowerSensor powerSensor1 annotation(
Placement(visible = true, transformation(origin = {14, -30}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
ThermoPower.Electrical.Generator generator1 annotation(
Placement(visible = true, transformation(origin = {44, -30}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Blocks.Continuous.FirstOrder firstOrder1 annotation(
Placement(visible = true, transformation(origin = {30, -70}, extent =
{{-10, -10}, {10, 10}}, rotation = 0)));
Modelica.Blocks.Interfaces.RealOutput y annotation(
Placement(visible = true, transformation(origin = {108, -70}, extent =
{{-10, -10}, {10, 10}}, rotation = 0), iconTransformation(origin = {108,
-70}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
equation
connect(firstOrder1.y, y) annotation(
Line(points = {{42, -70}, {100, -70}, {100, -70}, {108, -70}}, color = {0,
0, 127}));
connect(powerSensor1.power, firstOrder1.u) annotation(
Line(points = {{6, -42}, {6, -42}, {6, -70}, {18, -70}, {18, -70}}, color
= {0, 0, 127}));
connect(powerSensor1.flange_b, generator1.shaft) annotation(
Line(points = {{24, -30}, {36, -30}, {36, -30}, {36, -30}}));
connect(SteamTurbine.shaft_b, powerSensor1.flange_a) annotation(
Line(points = {{-12, -30}, {4, -30}, {4, -30}, {4, -30}}));
connect(SteamTurbine.outlet, TSteam_Outlet.inlet) annotation(
Line(points = {{-10, -20}, {0, -20}, {0, 0}, {10, 0}}, color = {0, 0,
255}));
connect(TSteam_Outlet.outlet, SteamSink.flange) annotation(
Line(points = {{22, 0}, {38, 0}}, color = {0, 0, 255}));
connect(HX.waterOut, SteamTurbine.inlet) annotation(
Line(points = {{-30, 20}, {-30, -20}}, color = {0, 0, 255}));
connect(TWater_Inlet.outlet, HX.waterIn) annotation(
Line(points = {{-30, 54}, {-30, 54}, {-30, 40}, {-30, 40}}, color = {0, 0,
255}));
connect(WaterSource.flange, TWater_Inlet.inlet) annotation(
Line(points = {{-30, 82}, {-30, 82}, {-30, 66}, {-30, 66}}, color = {0, 0,
255}));
connect(TGas_Outlet.outlet, FlueGasSink.flange) annotation(
Line(points = {{6, 30}, {14, 30}, {14, 30}, {22, 30}, {22, 30}, {22, 30}},
color = {159, 159, 223}));
connect(HX.gasOut, TGas_Outlet.inlet) annotation(
Line(points = {{-20, 30}, {-13, 30}, {-13, 30}, {-6, 30}, {-6, 30}, {-6,
30}, {-6, 30}, {-6, 30}}, color = {159, 159, 223}));
connect(TGas_Inlet.outlet, HX.gasIn) annotation(
Line(points = {{-52, 30}, {-46, 30}, {-46, 30}, {-40, 30}, {-40, 30},
{-40, 30}, {-40, 30}, {-40, 30}}, color = {159, 159, 223}));
connect(FlueGasSource.flange, TGas_Inlet.inlet) annotation(
Line(points = {{-82, 30}, {-64, 30}, {-64, 30}, {-64, 30}}, color = {159,
159, 223}));
connect(HX.gasOut, HX.gasIn) annotation(
Line(points = {{-20, 30}, {-40, 30}}, color = {159, 159, 223}));
annotation(
uses(ThermoPower(version = "3.1"), Modelica(version = "3.2.3")));end
HX_Turbine_Check;