Modelica.UsersGuide Modelica.UsersGuide

Package Modelica is a standardized and pre-defined package that is developed together with the Modelica language from the Modelica Association, see https://www.Modelica.org. It is also called Modelica Standard Library. It provides constants, types, connectors, partial models and model components in various disciplines.

This is a short User's Guide for the overall library. Some of the main sublibraries have their own User's Guides that can be accessed by the following links:

ComplexBlocks Library of basic input/output control blocks with Complex signals
Digital Library for digital electrical components based on the VHDL standard (2-,3-,4-,9-valued logic)
Dissipation Library of functions for convective heat transfer and pressure loss characteristics
Fluid Library of 1-dim. thermo-fluid flow models using the Modelica.Media media description
FluidHeatFlow Library of simple components for 1-dimensional incompressible thermo-fluid flow models
FluxTubes Library for modelling of electromagnetic devices with lumped magnetic networks
FundamentalWave Library for magnetic fundamental wave effects in electric machines
FundamentalWave Library for quasi static fundamental wave electric machines
Machines Library for electric machines
Media Library of media property models
MultiBody Library to model 3-dimensional mechanical systems
MultiPhase Library for electrical components of one or more phases
PowerConverters Library for rectifiers, inverters and DC/DC converters
QuasiStationary Library for quasi-stationary electrical singlephase and multiphase AC simulation
Rotational Library to model 1-dimensional, rotational mechanical systems
SIunits Library of type definitions based on SI units according to ISO 31-1992
Spice3 Library for components of the Berkeley SPICE3 simulator
StateGraph Library to model discrete event and reactive systems by hierarchical state machines
Translational Library to model 1-dimensional, translational mechanical systems
Utilities Library of utility functions especially for scripting (Files, Streams, Strings, System)

Extends from Modelica.Icons.Information (Icon for general information packages).

Package Content

Name Description
Modelica.UsersGuide.Overview Overview Overview of Modelica Library
Modelica.UsersGuide.Connectors Connectors Connectors
Modelica.UsersGuide.Conventions Conventions Conventions
Modelica.UsersGuide.ParameterDefaults ParameterDefaults Parameter defaults
Modelica.UsersGuide.ReleaseNotes ReleaseNotes Release notes
Modelica.UsersGuide.Contact Contact Contact

Modelica.UsersGuide.Overview Modelica.UsersGuide.Overview

The Modelica Standard Library consists of the following main sub-libraries:

Library Components Description
Analog
Analog electric and electronic components, such as resistor, capacitor, transformers, diodes, transistors, transmission lines, switches, sources, sensors.
Digital
Digital electrical components based on the VHDL standard, like basic logic blocks with 9-value logic, delays, gates, sources, converters between 2-, 3-, 4-, and 9-valued logic.
Machines
Electrical asynchronous-, synchronous-, and DC-machines (motors and generators) as well as 3-phase transformers.
FluxTubes
Based on magnetic flux tubes concepts. Especially to model electro-magnetic actuators. Nonlinear shape, force, leakage, and material models. Material data for steel, electric sheet, pure iron, Cobalt iron, Nickel iron, NdFeB, Sm2Co17, and more.
Translational
1-dim. mechanical, translational systems, e.g., sliding mass, mass with stops, spring, damper.
Rotational
1-dim. mechanical, rotational systems, e.g., inertias, gears, planetary gears, convenient definition of speed/torque dependent friction (clutches, brakes, bearings, ..)

MultiBody 3-dim. mechanical systems consisting of joints, bodies, force and sensor elements. Joints can be driven by drive trains defined by 1-dim. mechanical system library (Rotational). Every component has a default animation. Components can be arbitrarily connected together.
Fluid
1-dim. thermo-fluid flow in networks of vessels, pipes, fluid machines, valves and fittings. All media from the Modelica.Media library can be used (so incompressible or compressible, single or multiple substance, one or two phase medium).
Media
Large media library providing models and functions to compute media properties, such as h = h(p,T), d = d(p,T), for the following media:
  • 1240 gases and mixtures between these gases.
  • incompressible, table based liquids (h = h(T), etc.).
  • compressible liquids
  • dry and moist air
  • high precision model for water (IF97).
FluidHeatFlow, HeatTransfer Simple thermo-fluid pipe flow, especially to model cooling of machines with air or water (pipes, pumps, valves, ambient, sensors, sources) and lumped heat transfer with heat capacitors, thermal conductors, convection, body radiation, sources and sensors.

Blocks
Input/output blocks to model block diagrams and logical networks, e.g., integrator, PI, PID, transfer function, linear state space system, sampler, unit delay, discrete transfer function, and/or blocks, timer, hysteresis, nonlinear and routing blocks, sources, tables.
StateGraph
Hierarchical state machines with a similar modeling power as Statecharts. Modelica is used as synchronous action language, i.e., deterministic behavior is guaranteed
 A = [1,2,3;
   3,4,5;
   2,1,4];
 b = {10,22,12};
 x = Matrices.solve(A,b);
 Matrices.eigenValues(A);
 
Math, Utilities
Functions operating on vectors and matrices, such as for solving linear systems, eigen and singular values etc., and functions operating on strings, streams, files, e.g., to copy and remove a file or sort a vector of strings.

Extends from Modelica.Icons.Information (Icon for general information packages).

Modelica.UsersGuide.Connectors Modelica.UsersGuide.Connectors

The Modelica standard library defines the most important elementary connectors in various domains. If any possible, a user should utilize these connectors in order that components from the Modelica Standard Library and from other libraries can be combined without problems. The following elementary connectors are defined (the meaning of potential, flow, and stream variables is explained in section "Connector Equations" below):

domain potential
variables
flow
variables
stream
variables
connector definition icons
electrical
analog
electrical potential electrical current Modelica.Electrical.Analog.Interfaces
Pin, PositivePin, NegativePin
electrical
multi-phase
vector of electrical pins Modelica.Electrical.MultiPhase.Interfaces
Plug, PositivePlug, NegativePlug
electrical
space phasor
2 electrical potentials 2 electrical currents Modelica.Electrical.Machines.Interfaces
SpacePhasor
quasi
stationary
single phase
complex electrical potential complex electrical current Modelica.Electrical.QuasiStationary.SinglePhase.Interfaces
Pin, PositivePin, NegativePin
quasi
stationary
multi-phase
vector of quasi stationary single phase pins Modelica.Electrical.QuasiStationary.MultiPhase.Interfaces
Plug, PositivePlug, NegativePlug
electrical
digital
Integer (1..9) Modelica.Electrical.Digital.Interfaces
DigitalSignal, DigitalInput, DigitalOutput
magnetic
flux tubes
magnetic potential magnetic flux Modelica.Magnetic.FluxTubes.Interfaces
MagneticPort, PositiveMagneticPort,
NegativeMagneticPort
magnetic
fundamental
wave
complex magnetic potential complex magnetic flux Modelica.Magnetic.FundamentalWave.Interfaces
MagneticPort, PositiveMagneticPort,
NegativeMagneticPort
translational distance cut-force Modelica.Mechanics.Translational.Interfaces
Flange_a, Flange_b
rotational angle cut-torque Modelica.Mechanics.Rotational.Interfaces
Flange_a, Flange_b
3-dim.
mechanics
position vector
orientation object
cut-force vector
cut-torque vector
Modelica.Mechanics.MultiBody.Interfaces
Frame, Frame_a, Frame_b, Frame_resolve
simple
fluid flow
pressure
specific enthalpy
mass flow rate
enthalpy flow rate
Modelica.Thermal.FluidHeatFlow.Interfaces
FlowPort, FlowPort_a, FlowPort_b
thermo
fluid flow
pressure mass flow rate specific enthalpy
mass fractions
Modelica.Fluid.Interfaces
FluidPort, FluidPort_a, FluidPort_b
heat
transfer
temperature heat flow rate Modelica.Thermal.HeatTransfer.Interfaces
HeatPort, HeatPort_a, HeatPort_b
blocks Real variable
Integer variable
Boolean variable
Modelica.Blocks.Interfaces
RealSignal, RealInput, RealOutput
IntegerSignal, IntegerInput, IntegerOutput
BooleanSignal, BooleanInput, BooleanOutput
complex
blocks
Complex variable Modelica.ComplexBlocks.Interfaces
ComplexSignal, ComplexInput, ComplexOutput
state
machine
Boolean variables
(occupied, set,
available, reset)
Modelica.StateGraph.Interfaces
Step_in, Step_out, Transition_in, Transition_out

In all domains, usually 2 connectors are defined. The variable declarations are identical, only the icons are different in order that it is easy to distinguish connectors of the same domain that are attached at the same component.

Hierarchical Connectors

Modelica supports also hierarchical connectors, in a similar way as hierarchical models. As a result, it is, e.g., possible, to collect elementary connectors together. For example, an electrical plug consisting of two electrical pins can be defined as:

connector Plug
   import Modelica.Electrical.Analog.Interfaces;
   Interfaces.PositivePin phase;
   Interfaces.NegativePin ground;
end Plug;

With one connect(..) equation, either two plugs can be connected (and therefore implicitly also the phase and ground pins) or a Pin connector can be directly connected to the phase or ground of a Plug connector, such as "connect(resistor.p, plug.phase)".

Connector Equations

The connector variables listed above have been basically determined with the following strategy:

  1. State the relevant balance equations and boundary conditions of a volume for the particular physical domain.
  2. Simplify the balance equations and boundary conditions of (1) by taking the limit of an infinitesimal small volume (e.g., thermal domain: temperatures are identical and heat flow rates sum up to zero).
  3. Use the variables needed for the balance equations and boundary conditions of (2) in the connector and select appropriate Modelica prefixes, so that these equations are generated by the Modelica connection semantics.

The Modelica connection semantics is sketched at hand of an example: Three connectors c1, c2, c3 with the definition

connector Demo
  Real        p;  // potential variable
  flow   Real f;  // flow variable
  stream Real s;  // stream variable
end Demo;

are connected together with

   connect(c1,c2);
   connect(c1,c3);

then this leads to the following equations:

  // Potential variables are identical
  c1.p = c2.p;
  c1.p = c3.p;

  // The sum of the flow variables is zero
  0 = c1.f + c2.f + c3.f;

  /* The sum of the product of flow variables and upstream stream variables is zero
     (this implicit set of equations is explicitly solved when generating code;
     the "<undefined>" parts are defined in such a way that
     inStream(..) is continuous).
  */
  0 = c1.f*(if c1.f > 0 then s_mix else c1.s) +
      c2.f*(if c2.f > 0 then s_mix else c2.s) +
      c3.f*(if c3.f > 0 then s_mix else c3.s);

  inStream(c1.s) = if c1.f > 0 then s_mix else <undefined>;
  inStream(c2.s) = if c2.f > 0 then s_mix else <undefined>;
  inStream(c3.s) = if c3.f > 0 then s_mix else <undefined>;

Extends from Modelica.Icons.Information (Icon for general information packages).

Modelica.UsersGuide.ParameterDefaults Modelica.UsersGuide.ParameterDefaults

In this section the convention is summarized how default parameters are handled in the Modelica Standard Library (since version 3.0).

Many models in this library have parameter declarations to define constants of a model that might be changed before simulation starts. Example:

model SpringDamper
parameter Real c(final unit="N.m/rad")    = 1e5 "Spring constant";
parameter Real d(final unit="N.m.s/rad")  = 0   "Damping constant";
parameter Modelica.SIunits.Angle phi_rel0 = 0   "Unstretched spring angle";
...
end SpringDamper;

In Modelica it is possible to define a default value of a parameter in the parameter declaration. In the example above, this is performed for all parameters. Providing default values for all parameters can lead to errors that are difficult to detect, since a modeler may have forgotten to provide a meaningful value (the model simulates but gives wrong results due to wrong parameter values). In general the following basic situations are present:

  1. The parameter value could be anything (e.g., a spring constant or a resistance value) and therefore the user should provide a value in all cases. A Modelica translator should warn, if no value is provided.
  2. The parameter value is not changed in > 95 % of the cases (e.g., initialization or visualization parameters, or parameter phi_rel0 in the example above). In this case a default parameter value should be provided, in order that the model or function can be conveniently used by a modeler.
  3. A modeler would like to quickly utilize a model, e.g., In all these cases, it would be not practical, if the modeler would have to provide explicit values for all parameters first.

To handle the conflicting goals of (1) and (3), the Modelica Standard Library uses two approaches to define default parameters, as demonstrated with the following example:

model SpringDamper
parameter Real c(final unit="N.m/rad"  , start=1e5) "Spring constant";
parameter Real d(final unit="N.m.s/rad", start=  0) "Damping constant";
parameter Modelica.SIunits.Angle phi_rel0 = 0       "Unstretched spring angle";
...
end SpringDamper;

SpringDamper sp1;              // warning for "c" and "d"
SpringDamper sp2(c=1e4, d=0);  // fine, no warning

Both definition forms, using a "start" value (for "c" and "d") and providing a declaration equation (for "phi_rel0"), are valid Modelica and define the value of the parameter. By convention, it is expected that Modelica translators will trigger a warning message for parameters that are not defined by a declaration equation, by a modifier equation or in an initial equation/algorithm section. A Modelica translator might have options to change this behavior, especially, that no messages are printed in such cases and/or that an error is triggered instead of a warning.

Extends from Modelica.Icons.Information (Icon for general information packages).

Modelica.UsersGuide.Contact Modelica.UsersGuide.Contact

The Modelica Standard Library (this Modelica package) is developed by contributors from different organizations (see list below). It is licensed under the BSD 3-Clause License by:

Modelica Association
(Ideella Föreningar 822003-8858 in Linköping)
c/o PELAB, IDA, Linköpings Universitet
S-58183 Linköping
Sweden
email: Board@Modelica.org
web: https://www.Modelica.org

The development of this Modelica package, starting with version 3.2.3, is organized by:
Thomas Beutlich and Dietmar Winkler

The development of this Modelica package of version 3.2.2 was organized by:
Anton Haumer
Technical Consulting & Electrical Engineering
D-93049 Regensburg
Germany
email: A.Haumer@Haumer.at

The development of this Modelica package up to and including version 3.2.1 was organized by:
Martin Otter
German Aerospace Center (DLR)
Robotics and Mechatronics Center (RMC)
Institute of System Dynamics and Control (SR)
Postfach 1116
D-82230 Wessling
Germany
email: Martin.Otter@dlr.de

Since end of 2007, the development of the sublibraries of package Modelica is organized by personal and/or organizational library officers assigned by the Modelica Association. They are responsible for the maintenance and for the further organization of the development. Other persons may also contribute, but the final decision for library improvements and/or changes is performed by the responsible library officer(s). In order that a new sublibrary or a new version of a sublibrary is ready to be released, the responsible library officers report the changes to the members of the Modelica Association and the library is made available for beta testing to interested parties before a final decision. A new release of a sublibrary is formally decided by voting of the Modelica Association members.

As of March 21st, 2018, the following library officers are assigned:

Sublibraries Library officers
Blocks Martin Otter, Anton Haumer
ComplexBlocks Anton Haumer, Christian Kral
Blocks.Tables Thomas Beutlich, Martin Otter, Anton Haumer
StateGraph Martin Otter, Hans Olsson
Electrical.Analog Christoph Clauss, Kristin Majetta, Christian Kral
Electrical.Digital Christoph Clauss, Kristin Majetta
Electrical.Machines Anton Haumer, Christian Kral
Electrical.Multiphase Anton Haumer, Christian Kral
Electrical.PowerConverters Christian Kral, Anton Haumer
Electrical.QuasiStationary Anton Haumer, Christian Kral
Electrical.Spice3 Christoph Clauss, Kristin Majetta
Magnetic.FluxTubes Thomas Bödrich, Johannes Ziske
Magnetic.FundamentalWave Christian Kral, Anton Haumer
Magnetic.QuasiStatic Christian Kral, Anton Haumer
Mechanics.MultiBody Jakub Tobolar, Martin Otter
Mechanics.Rotational Jakub Tobolar, Martin Otter, Anton Haumer, Christian Kral
Mechanics.Translational Anton Haumer, Jakub Tobolar, Martin Otter, Christian Kral
Fluid Rüdiger Franke, Francesco Casella, Hubertus Tummescheit
Fluid.Dissipation Stefan Wischhusen, Francesco Casella
Media Hubertus Tummescheit, Francesco Casella, Rüdiger Franke
Thermal.FluidHeatFlow Anton Haumer, Christian Kral
Thermal.HeatTransfer Anton Haumer, Christian Kral
Math Martin Otter, Hans Olsson
ComplexMath Anton Haumer, Martin Otter, Christian Kral
Utilities Martin Otter, Hans Olsson, Dag Brück
Constants Martin Otter, Hans Olsson
Icons Christian Kral
SIunits Martin Otter, Christian Kral
C-Sources Thomas Beutlich, Hans Olsson, Martin Sjölund
Reference Dietmar Winkler, Hans Olsson
Services Hans Olsson, Martin Otter
Complex Anton Haumer, Christian Kral
Test Leo Gall, Martin Otter
TestOverdetermined Leo Gall, Martin Otter
ObsoleteModelica3 Hans Olsson, Martin Otter

The following people have directly contributed to the implementation of the Modelica package (many more people have contributed to the design):

Marcus Baur Institute of System Dynamics and Control
DLR, German Aerospace Center,
Oberpfaffenhofen, Germany
Complex
Modelica.Math.Vectors
Modelica.Math.Matrices
Peter Beater University of Paderborn, Germany Modelica.Mechanics.Translational
Thomas Beutlich ESI ITI GmbH, Germany Modelica.Blocks.Sources.CombiTimeTable
Modelica.Blocks.Tables
Thomas Bödrich Dresden University of Technology, Germany Modelica.Magnetic.FluxTubes
Dag Brück Dassault Systèmes AB, Lund, Sweden Modelica.Utilities
Francesco Casella Politecnico di Milano, Milano, Italy Modelica.Fluid
Modelica.Media
Christoph Clauss until 2016:
Fraunhofer Institute for Integrated Circuits,
Dresden, Germany
Modelica.Electrical.Analog
Modelica.Electrical.Digital
Modelica.Electrical.Spice3
Jonas Eborn Modelon AB, Lund, Sweden Modelica.Media
Hilding Elmqvist Mogram AB, Lund, Sweden
until 2015:
Dassault Systèmes AB, Lund, Sweden
Modelica.Mechanics.MultiBody
Modelica.Fluid
Modelica.Media
Modelica.StateGraph
Modelica.Utilities
Conversion from 1.6 to 2.0
Rüdiger Franke ABB Corporate Research,
Ladenburg, Germany
Modelica.Fluid
Modelica.Media
Manuel Gräber Institut für Thermodynamik,
Technische Universität Braunschweig, Germany
Modelica.Fluid
Anton Haumer Consultant, Regensburg,
Germany
Modelica.ComplexBlocks
Modelica.Electrical.Machines
Modelica.Electrical.Multiphase
Modelica.Electrical.QuasiStationary
Modelica.Magnetics.FundamentalWave
Modelica.Mechanics.Rotational
Modelica.Mechanics.Translational
Modelica.Thermal.FluidHeatFlow
Modelica.Thermal.HeatTransfer
Modelica.ComplexMath
Conversion from 1.6 to 2.0
Conversion from 2.2 to 3.0
Hans-Dieter Joos Institute of System Dynamics and Control
DLR, German Aerospace Center,
Oberpfaffenhofen, Germany
Modelica.Math.Matrices
Christian Kral Modeling and Simulation of Electric Machines, Drives and Mechatronic Systems,
Vienna, Austria
Modelica.ComplexBlocks
Modelica.Electrical.Machines
Modelica.Electrical.MultiPhase
Modelica.Electrical.QuasiStationary
Modelica.Magnetics.FundamentalWave
Modelica.Mechanics.Rotational
Modelica.Mechanics.Translational
Modelica.Thermal.FluidHeatFlow
Modelica.Thermal.HeatTransfer
Modelica.ComplexMath
Sven Erik Mattsson until 2015:
Dassault Systèmes AB, Lund, Sweden
Modelica.Mechanics.MultiBody
Hans Olsson Dassault Systèmes AB, Lund, Sweden Modelica.Blocks
Modelica.Math.Matrices
Modelica.Utilities
Conversion from 1.6 to 2.0
Conversion from 2.2 to 3.0
Martin Otter Institute of System Dynamics and Control
DLR, German Aerospace Center,
Oberpfaffenhofen, Germany
Complex
Modelica.Blocks
Modelica.Fluid
Modelica.Mechanics.MultiBody
Modelica.Mechanics.Rotational
Modelica.Mechanics.Translational
Modelica.Math
Modelica.ComplexMath
Modelica.Media
Modelica.SIunits
Modelica.StateGraph
Modelica.Thermal.HeatTransfer
Modelica.Utilities
ModelicaReference
Conversion from 1.6 to 2.0
Conversion from 2.2 to 3.0
Katrin Prölß Modelon Deutschland GmbH, Hamburg, Germany
until 2008:
Department of Technical Thermodynamics,
Technical University Hamburg-Harburg,
Germany
Modelica.Fluid
Modelica.Media
Christoph C. Richter until 2009:
Institut für Thermodynamik,
Technische Universität Braunschweig,
Germany
Modelica.Fluid
Modelica.Media
André Schneider Fraunhofer Institute for Integrated Circuits,
Dresden, Germany
Modelica.Electrical.Analog
Modelica.Electrical.Digital
Christian Schweiger until 2006:
Institute of System Dynamics and Control,
DLR, German Aerospace Center,
Oberpfaffenhofen, Germany
Modelica.Mechanics.Rotational
ModelicaReference
Conversion from 1.6 to 2.0
Michael Sielemann Modelon Deutschland GmbH, Munich, Germany
previously at:
Institute of System Dynamics and Control
DLR, German Aerospace Center,
Oberpfaffenhofen, Germany
Modelica.Fluid
Modelica.Media
Michael Tiller Xogeny Inc., Canton, MI, U.S.A.
previously at:
Emmeskay, Inc., Dearborn, MI, U.S.A.
previously at:
Ford Motor Company, Dearborn, MI, U.S.A.
Modelica.Media
Modelica.Thermal.HeatTransfer
Hubertus Tummescheit Modelon, Inc., Hartford, CT, U.S.A. Modelica.Media
Modelica.Thermal.HeatTransfer
Thorsten Vahlenkamp until 2010:
XRG Simulation GmbH, Hamburg, Germany
Modelica.Fluid.Dissipation
Nico Walter Master thesis at HTWK Leipzig
(Prof. R. Müller) and
DLR Oberpfaffenhofen, Germany
Modelica.Math.Matrices
Michael Wetter Lawrence Berkeley National Laboratory, Berkeley, CA, U.S.A. Modelica.Fluid
Hans-Jürg Wiesmann Switzerland Modelica.ComplexMath
Stefan Wischhusen XRG Simulation GmbH, Hamburg, Germany Modelica.Fluid.Dissipation
Modelica.Media

Extends from Modelica.Icons.Contact (Icon for contact information).

Automatically generated Mon Oct 1 14:50:43 2018.