A simulation for electricity transmission using Modelica language. Since all the tools come from OpenModelica (a free tool), you can easily start and test the simulation in any OS. See the following link about OpenModelica: https://www.openmodelica.org/

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Modelica Tutorial
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OpenModelica
• OS
- Linux
- Windows
- Mac
ØPartly supported
ØInstall
• Homebrew
• Macport
- Virtual Machine (ubuntu)
Ø https://openmodelica.org/download/virtual-
machine
Ø Installation
1. Install virtualbox
2. Download box file, and vmdk file in same
directory
3. Double click the box file
Ø Bug: cannot login
• Change GUI manager
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1. Modelica introduction
2. Thermal simulation using Modelica
3. Exercise1: RL Circuit
4. Exercise2: Transmission Loss
5. Exercise3: Power World

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What is Modelica?
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TUTORIAL – COURSE
Introduction to Object-Oriented
Modeling and Simulation with Modelica
Using OpenModelica
Peter Fritzson
Copyright (c) Open Source Modelica Consortium
Version 2012
https://www.modelica.org/libraries
A language for modeling of
complex physical system.
Primarydesigned for simulation.

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What is Modelica?
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TUTORIAL – COURSE
Introduction to Object-Oriented
Modeling and Simulation with Modelica
Using OpenModelica
Peter Fritzson
Copyright (c) Open Source Modelica Consortium
Version 2012
https://www.modelica.org/libraries
A language for modeling of
complex physical system.
Combine multi-domainmodeling

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What is Modelica?
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Declarative language
Equations and mathematicalfunctions allow acausal modeling,
high level specification,increasedcorrectness
Multi-domain modeling
Combine electrical,mechanical,thermodynamic,hydraulic,
biological,control,event, real-time,etc…
Everything is a class
Strongly typed object-orientedlanguage with a general class
concept, Java & MATLAB-like syntax
Visual component programming
Hierarchical system architecture capabilities
Efficient, non-proprietary
Efficiencycomparable to C; advanced equation compilation,
e.g. 300 000 equations,~ 150 000 lines on standard PC

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Free/Commercial tools
• Simulator
- Commercial
ØDymola
ØCyModelica
ØWoflram
ØSimulationX
- Free
ØOpenModelica
ØJModelica.org
ØModelicac
• Editor
- Modelica mode for emacs
- UltraEdit
- Modelica Plugin (for Eclipse)
- Modelica Sublime Text Package
- OMEditor
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• Developer site
- https://modelica.org/tools

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Modelica Free/Commercial Libraries
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• Modelica Library
- Modelica
- Power system
- Vehicle
- Mathematics
- Chemical
- Building
https://www.modelica.org/libraries

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Modelica Tutorial
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• Exercise 1
- RL Circuit model
• Exercise 2
- TransmissionLoss model
• Exercise 3
- Power World

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Exercise 1: RL Circuit
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• Goal
- Making a basic RL circuit model using Modelica language
- Executing a simulationand plottingthe result
- Understanding the relationshipbetween electrical-thermalenergy
• Library
- Modelica library

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Exercise 1: RLC Circuit Modeling
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Open the OMEdit

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1. Make a new Package “RLCircuit”
2. Make a new Model “Resistor”
3. Add a extends model
4. Add a parameter “R”
5. Add a equation

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extends Modelica.Electrical.Analog.Interfaces.OnePort;
parameter Modelica.SIunits.Resistance R(start=1);
equation
v = R * i;

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“partial” means this model is incomplete

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SI => Modelica.SIunits
import SI = Modelica.SIunits;

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model Resistor
equation
v = p.v - nv;
0 = p.i - n.i;
i = p.i;
v = R * i;
end Resistor

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You can check your code here

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1. Make a new model “RLCircuit” in RLCircuit package
2. Add Inductor, Ground, and sinVoltage from
Modelica.Electrical.Analog, and Resistor
3. Connect each other

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1. Change the stoptime
2. simulate the model

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Exercise 1: Simulation result
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Choose the resistor1.v

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1. Right click the RLCircuit
2. Click the “Duplicate”
3. Choose RLCircuit package as the “Path”
4. Choose the new model

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1. Right click the resistance
2. Delete the block
3. Replace the resistance to
Modelica.Electrical.Analog.Basic.Resistor

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1. Add FixedTemperature from
Modelica.Thermal.HeatTransfer.Sources.FixedTemperature
2. Connect to the replaced resistor

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Simulation results
1. Click the LossPower and v in RLCircuit2
2. Compare the result

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New plot window

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Exercise 2: Transmission Loss
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• Goal
- Making a simple model representingtransmissionloss
using PowerSystems library
- Using the icon setting
- Understanding the outer/inner variables
• Library
- PowerSystems

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1. Open File->System Libraries->PowerSystems
2. Make a new model

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extends PowerSystems.Basic.Icons.Block;
Icon setting

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Click the icon view
Icon setting

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Icon setting

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1. Extend PartialTwoTerminal
2. Add three variables
You can search the PartialTwoTerminal here
Parameter of the line model

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Replaceable package inherits all functions/variables/settings
from PowerSystems library
Every model in PowerSystems inherits this PhaseSystem
• DC or AC
• Phase number
• Frequency

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1. Add equation
PhaseSystem.m: Number of reference angle
DC: m = 0
AC: m > 0
Equation of the line model

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if PhaseSystem.m > 0 then
omegaRef = der(PhaseSystem.thetaRef(terminal_p.theta));
else
omegaRef = 0;
end if;
v = R * i + omegaRef * L * j(i);
zeros(PhaseSystem.n) = terminal_p.i + terminal_n.i;
if PhaseSystem.m > 0 then
terminal_p.theta = terminal_n.theta;
end if
Equation of the line model

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Simulationof the line model

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1. Set 1. FixedVoltageSource, 2. FixedCurrennt, and 3. System
from Powersystem.Generic
2. Open the parameter window of the FixedCurrent by double
click and change the parameter
Simulationof the line model

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1. Set 1. FixedVoltageSource, 2. FixedCurrennt, and 3. System
from Powersystem.Generic
2. Open the parameter window of the FixedCurrent by double
click and change the parameter
Simulationof the line model

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1. Confirm your code is correct
Simulationof the line model

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System: an interface of PhaseSystem setting
”inner” works as a global variable
• Omega, theta, and frequency
• DC/AC/AC(3phase)
• Initial value
Simulationof the line model

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System: an interface of PhaseSystem setting
”inner” works as a global variable
• Omega, theta, and frequency
• DC/AC/AC(3phase)
• Initial value
inner PowerSystems.Systemsystem(…
Simulationof the line model

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* Modelica Advanced Tutorial: Developing Modeling Library, Martin Otter, Hilding Elmqvist

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By clicking the information button, you can
see the detailed information of the “System”.
Simulationof the line model

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The result is constant value
Simulationof the line model

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Exercise 3: Power World
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• Goal
- Simulatingthe simplifiedpower grid including
ØVoltage
ØCurrent
ØFrequency
- Considering transmissionloss,and voltage conversion
- Using dynamic wind and electricityconsumptiondata
• Library
- PowerSystems
* The Power World uses Generic components
with the quasi-static ThreePhase_dq because
fast electrical transients and asymmetries are
neglected. For more precise simulation of
power grid, you can use the SPOT from
PowerSystems supporting AC 3 phase.

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Exercise 3: Power World
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• Goal
- Simulatingthe simplifiedpower grid including
ØVoltage
ØCurrent
ØFrequency
- Considering transmissionloss,and voltage conversion
- Using dynamic wind and electricityconsumptiondata
• Library
- PowerSystems
* The Power World uses Generic components
with the quasi-static ThreePhase_dq because
fast electrical transients and asymmetries are
neglected. For more precise simulation of
power grid, you can use the SPOT from
PowerSystems supporting AC 3 phase.

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Exercise 3: Power World
1. Add System from PowerSystems
2. Add PowerPlant, HydroPlant, WindFarm, and City
from PowerSystems.Examples.Components

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You can check the content by
1. Right click the block
2. Choose “Open Class"
Exercise 3: Power World

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Exercise 3: Power World

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1. Click the “Text View”
2. Change the WindFarm setting
Exercise 3: Power World

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windFarm1(redeclare package PhaseSystem = PowerSystems.PhaseSystems.DirectCurrent)
Exercise 3: Power World

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1. Add VoltageConverter,
Inverter and line
2. Double click and change
the parameter of
VoltageConverter to 380/50
3. Double click and change
the PotentialReference of
Inverter to false
Exercise 3: Power World

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1. Add VoltageConverter,
Inverter and line
2. Double click and change
the parameter of
VoltageConverter to 380/10
Exercise 3: Power World

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1. Add LoadDispatcher from
PowerSystems.Example.PowerWorld.Components
2. Add RealExpression from Modelica.Blocks.Sources
Exercise 3: Power World

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1. Double click the RealExpression
2. Set the output “y” as “system.omega/2/pi”
Exercise 3: Power World

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“pi” is defined in Modelica.Constants
1. Click “Text View”
2. Add ”import Modelica.Constants.pi;”
Exercise 3: Power World

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1. Just click “OK” when you connect
the LoadDispatcher and Plants
Exercise 3: Power World

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Exercise 3: Power World
1. Double click the ”system”
2. Change ini to “tr” (double quotation is required)
3. Change ftype_par to false

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Exercise 3: Power World
1. Change the stoptime to 86400
60 (sec) * 60 * 24 = 86400

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Simulationresult: Electricitydemand and supply

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Simulationresult: Wind

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Simulationresult: Frequency

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Simulationresult: Frequency
In the system, simulation is terminated
when the frequency exceed the limitation.

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Two Windfarm model

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Two Windfarm model

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SPOT: more precise power-system simulation
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* The Power World uses Generic components
with the quasi-static ThreePhase_dq because
fast electrical transients and asymmetries are
neglected. For more precise simulation of
power grid, you can use the SPOT from
PowerSystems supporting AC 3 phase.

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Thank you for your attention

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Converter
(DC/AC)
Energy
Consumer
Frequency
Data
PowerPlant

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HydroDispatch:
HydroDispatch[1] = hydroBase
HydroDispatch[2] = hydroDaily
HydroDispatch[3] = controlHydro
plantDispatch:
plantDispatch[1] = plantSchedule
plantDispatch[2] = secondaryControl
plantDispatch[3] = primaryControl
𝜃 = 𝜔 $ 2𝜋
LoadDispatcher

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PowerPlant
plantDispatch:
plantDispatch[1] = plantSchedule = fuel.u1
plantDispatch[2] = secondaryControl = add.u1
plantDispatch[3] = primaryControl

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HydroPlant
HydroDispatch:
HydroDispatch[1] = hydroBase = riverControl.u
HydroDispatch[2] = hydroDaily = add.u2
HydroDispatch[3] = controlHydro

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WindFarm
Wind Data

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City

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Open Modelica Library
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• Simulation Result
city
windFarm
hydroPlant
powerPlant

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IPSL
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