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Questions tagged [systemmodeler]

Wolfram SystemModeler, developed by Wolfram MathCore, is a platform for engineering as well as life science modeling and simulation based on the Modelica language.

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Numerical issues integrating a pulse signal that is delayed (fixedDelay)

I noted numerical issues integrating a pulse input that is delayed by a fixed amount of time in Modelica (using Wolfram System Modeler 4.3): model PulseTest "Test FixedDelay with Pulse Input"; Modelica.Blocks.Sources.Pulse pulse( …
gwr
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What are the differences between diffferent Modelica Simulation Environments?

There are different Modelica Simulation Environments, including Dymola, Wolfram SystemModeler, OpenModelica, and Jmodelica. So, I try to load a thermal fluid library(ThermoSysPro https://github.com/Dwarf-Planet-Project/ThermoSysPro), but except…
Jack
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Generate white noise in Modelica (SystemModeler)

I am trying to add measurement noise to a simulation. This is possible to do in for example Simulink but seems to be more difficult in Modelica and SystemModeler. Any ideas on how to do this?
sebnil
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Does Dymola have the similar function of "equation browser" like Wolfram system modeler?

Wolfram system modeler has a function called "equation browser", the youtube video here(at 20:58) gives an introduction about "equation browser", I am wondering if Dymola has the same function, it would be helpful to debug nonlinear system. Also, it…
Jack
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How to use boolean switches in Modelica to prevent draining a stock below zero?

Problem description I am building a library to support System Dynamics (SD) like modeling in Modelica. Unlike the freely available library by Cellier et al. I am convinced that one may well make use of acausal connectors: Transmitting the stock…
gwr
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Modelica variable not declared in this scope

The Modelica model below passes validation: model TestController parameter Real off[4] = fill(20, 4) "Radiator turn off threshold"; parameter Real on[4] = fill(19, 4) "Radiator turn on threshold"; discrete Modelica.Blocks.Interfaces.RealInput…
Sameer Puri
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How to use flexible array sizes within an expandable connector?

I would like to use expandable connector (e.g. a Bus-like structure) to model (mainly) input and output connections for more complex subsystems (An array will not allow having different units for its elements and flattened lists get unwieldly while…
gwr
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Can a parameter be used to set the unit attribute for a component?

So far, using Wolfram System Modeler 4.3 and 5.1 the following minimal example would compile without errors: model UnitErrorModel MyComponent c( hasUnit = "myUnit" ); block MyComponent parameter String hasUnit = "1"; output…
gwr
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Why are graphical annotations for connectors not inherited upon redeclaration?

I am creating a library for System Dynamics modeling which unlike the existing free library by Cellier is making use of acausal connectors. For "Flow" - Elements I have a GenericFlow class that defines the interfaces: partial model GenericFlow "Flow…
gwr
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How to make use of the unit attribute within a model in Modelica?

Motivation Modelica does store units of measurement (e.g. SI units and Non-SI units) as an attribute with regard to a variable. Here is an example for a Non-SI-unit: type Time_months = Real( quantity = "Time", unit = "mo", displayUnit = "months"…
gwr
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Modelica - Increment doesn't follow conditions

I am creating a Max Per Interval block in Wolfram System Modeler. To make it easy for me to explain, I just set the Max value to 10. block HighWaterMarkPerInterval extends Modelica.Blocks.Interfaces.SISO; protected Integer index; Real…
user3791725
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Modelica v4.0.0 Visualizers are Broken

I have recently migrated to modelica version 4.0.0, am am having some problems, it turns out that some visualizer settings for the SignalArrow and sensors, such as the absoluteSensor had their diameter settings removed, Changes in Modelica Version…
DrMrstheMonarch
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Derivative as divisor gives division by zero during initialization in Dymola

I build a model that includes a derivative of dy/dx=5, as shown in the following segment, but the model fails during initialization in Dymola, in another question, it has been answered. The reason is that at time=0, the values of der(x) and der(y)…
Jack
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How to have a causal connector with a replaceable type?

While the Advanced Modelica Tutorial: Developing Modelica Libraries is from 2003, I would still believe that the code from page 29 would give a causal connector (RealPort) with a replaceable type: connector RealPort replaceable type SignalType =…
gwr
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PI-Controller doesn't reach reference value with inverter and PMSM in Modelica

I'm trying to investigate the Modelica example Modelica.Electrical.Machines.Examples.SynchronousInductionMachines.SMPM_VoltageSource but I replaced the signalVoltage by an inverter and a PWM block signalPWM which is based on…
Moebo
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