A MODELICA-Based Object-Centric Virtual Power Electronics Laboratory - PowerPoint PPT Presentation

A MODELICA-Based Object-Centric Virtual Power Electronics Laboratory

Janhavi Agashe

V.V.Sastry

V.Ajjarapu

S.S.Venkata

Dept. Of Electrical & Computer Engineering

Iowa State University

• Power Electronics Simulators
• Object-Oriented Modeling Language – Modelica
• Modeling of Components in Modelica
• Various Models Developed
• Simulation Results
• Conclusions

North American Power Symposium 2002, Arizona State University, Tempe

System Area

System &

Control theory

Modeling &

Simulation

High Power Area

Low Power Area

Analog Electronics

Circuit Theory

Signal Processing

Electric machines

Power

Electronics

Solid-State Physics

Power Systems

Digital Electronics

Electromagnetics

Power Electronics

North American Power Symposium 2002, Arizona State University, Tempe

• A simulator for power electronic systems should
• Haveevent handling capabilities.
• Handle hybrid/ mixed-mode systems.
• Support multi-domain modeling.
• Widely used simulators: SABER, PSPICE, MATLAB/SIMULINK etc.
• Lack of Object-oriented features
• Closed modeling environment

North American Power Symposium 2002, Arizona State University, Tempe

• Developed by the Modelica Association, Germany
• Key Features
• Object-oriented modeling language
• Hierarchical structuring
• Reuse
• Effective in solving large and complex models
• Open Modeling Environment

North American Power Symposium 2002, Arizona State University, Tempe

• Additional Features
• Acausal modeling
• Ports are not committed to ‘input’ and ‘output’ early in the modeling/design process
• Simpler models
• More efficient simulation
• Multi-domain
• Electrical circuits, multi-body systems, drive trains, hydraulics, thermodynamic systems

North American Power Symposium 2002, Arizona State University, Tempe

• Additional Features (contd.)
• Several formalisms
• ODE, DAE, bond graphs, finite state automata, state charts
• Graphical user interfaces
• Icons representing model components
• Menu driven interface for modeling and simulation
• Standardization effort
• Group of internationally recognized and experienced researchers and companies worked for language and model development

North American Power Symposium 2002, Arizona State University, Tempe

• Model is derived as an extension of some base class using the “extends” statement
• Required variables are declared
• Necessary equations are defined in the “equation” section
• The “annotation” section defines the graphical symbol i.e. icon for the model
• The file is saved as “*.mo”

North American Power Symposium 2002, Arizona State University, Tempe

North American Power Symposium 2002, Arizona State University, Tempe

model Thyristor

constant Boolean DymolaCompatibility=true;

extends Modelica.Electrical.Analog.Interfaces.ThreePin;

Real Gate;

Real u;

Real GOp = 1.E-5;

Real RCl = 1.E-5;

Real i;

Boolean GATE;

Boolean Op(start=true);

equation

cont.v = Gate;

u = p.v-n.v;

i=p.i;

0=p.i+n.i;

GATE = if (Gate < 1.0) then false else true;

0 = if Op then i - GOp*(p.v - n.v) else (p.v - n.v) - RCl*i;

when (not (Op) and i < 0) or (Op and u > 0 and GATE) then

new(Op) = (not (Op) and i < 0) or (Op and not ((u > 0 and GATE)));

end when;

end Thyristor;

North American Power Symposium 2002, Arizona State University, Tempe

North American Power Symposium 2002, Arizona State University, Tempe

• Front-end
• Pre-processing tool that helps effective understanding and modeling
• DYMODRAW
• Simulation Engine
• For conversion DAE’s into state space form and solving them symbolically or with efficient numerical techniques.
• DYMOSIM. Any other simulator like ACSL, SIMULINK, etc. can also be used.
• Post-processing tool
• Visualization of dynamic behavior, 2-D or 3-D graphical view or animation.
• DYMOVIEW

North American Power Symposium 2002, Arizona State University, Tempe

GraphicalFront-end

Object-oriented Modeling

Simulation Engine

Post-processing Tool

North American Power Symposium 2002, Arizona State University, Tempe

Single Thyristor

Switch Library

Various Libraries

North American Power Symposium 2002, Arizona State University, Tempe

Connection of components

Entire Circuit & its Translation

North American Power Symposium 2002, Arizona State University, Tempe

Simulation Control

Plot Window & Output Variables

North American Power Symposium 2002, Arizona State University, Tempe

North American Power Symposium 2002, Arizona State University, Tempe

Firing Angle = 45 degrees

Firing Angle = 30 degrees

North American Power Symposium 2002, Arizona State University, Tempe

iout

Vout

North American Power Symposium 2002, Arizona State University, Tempe

Duty Ratio = 0.75

North American Power Symposium 2002, Arizona State University, Tempe

• Single Phase Thyristor Rectifier
• Three Phase Thyristor Rectifier
• Buck Chopper
• Boost Chopper
• Single Phase Square-Wave Inverter
• Three Phase Square-Wave Inverter
• Chopper-fed DC Motor Drive
• V/F control of Induction Motor

North American Power Symposium 2002, Arizona State University, Tempe

• Object-oriented modeling language enabled reuse of models, hierarchical structuring and easy maintenance of models
• The power electronics library using MODELICA has been developed at Iowa State University
• EE 452 experiments earlier written in DYMOLA have been designed around the new MODELICA library

North American Power Symposium 2002, Arizona State University, Tempe