drives using simulink

A Workshop on

Programming, Analysis and Simulation using Matlab- For

Electrical Engineering17-19 January,2008

G.H. Patel College of Engineering and Technology

Electrical Drives using Simulink toolbox of

Matlab

Presented by:

P.R.MankadElectrical Engineering Department,

Shri S’ad Vidya Mandal Institute of Technology, Bharuch

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What is Matlab?

The name MATLAB stands for matrix laboratory.

MATLAB® is a high-performance language for technical computing.

It integrates computation, visualization, and programming in an easy-to-use environment.

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Simulink

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What is Simulink? Simulink is a software package that enables

you to model, simulate, and analyze systems whose outputs change over time.

Such systems are often referred to as dynamic systems.

Simulink can be used to explore the behavior of a wide range of real-world dynamic systems, including electrical circuits, shock absorbers, braking systems, and many other electrical, mechanical, and thermodynamic systems.

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What Is Simulink? For modeling, Simulink provides a graphical

user interface (GUI) for building models as block diagrams, using click-and-drag mouse operations.

With this interface, you can draw the models just as you would with pencil and paper (or as most textbooks depict them).

Simulink includes a comprehensive block library of sinks, sources, linear and nonlinear components, and connectors. You can also customize and create your own blocks.

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What Is Simulink? After you define a model, you can simulate it,

using a choice of integration methods

Using scopes and other display blocks, you can see the simulation results while the simulation is running.

In addition, you can change parameters and immediately see what happens, for "what if" exploration.

The simulation results can be put in the MATLAB workspace for postprocessing and visualization.

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How Simulink Works? Simulating a dynamic system is a two-step

process with Simulink.

First, you create a graphical model of the system to be simulated, using the Simulink model editor.

The model depicts the time-dependent mathematical relationships among the system's inputs, states, and outputs

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How Simulink Works? Second we use Simulink to simulate the

behavior of the system over a specified time span. Simulink uses information that you entered into the model to perform the simulation

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Modeling Dynamic Systems Simulink provides a library browser that

allows you to select blocks from libraries of standard blocks and a graphical editor that allows you to draw lines connecting the blocks.

You can model virtually any real-world dynamic system by selecting and interconnecting the appropriate Simulink blocks. Skip

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Block Diagrams A Simulink block diagram is a pictorial model

of a dynamic system. It consists of a set of symbols, called blocks,

interconnected by lines.

Each block represents an elementary dynamic system that produces an output either continuously (a continuous block) or at specific points in time (a discrete block).

The lines represent connections of block inputs to block outputs.

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Example-1: This example shows

you how to build a model.

The model integrates a sine wave and displays the result along with the sine wave.

The block diagram of the model looks like this.

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How to bulild simple model To create the model,

first enter ‘simulink’ in the MATLAB command window.

On Microsoft Windows, the Simulink Library Browser appears as shown.

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How to build simple model To create a new

model on Windows, select the New Model button on the Library Browser's toolbar

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How to bulild simple model

To create this model, you need to copy blocks into the model from the following Simulink block libraries:

Sources library (the Sine Wave block) Sinks library (the Scope block) Continuous library (the Integrator block) Signals & Systems library (the Mux block)

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How to bulild simple model You can copy a Sine Wave

block from the Sources library, using the Library Browser.

To copy the Sine Wave block from the Library Browser, click the Sine Wave node to select the Sine Wave block and drag it to new model window.

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How to bulild simple model Similarly copy

integrator bloack from continuous library, mux from signals and systems library block and scope from sink.

Connect sine wave block to other two items using mouse.

Connect output of mux to a scope

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How to bulild simple model To simulate the

model, click on ‘start’ from the simulation menu.

See the results on scope.

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The Library Blocks The Continuous

library

It contains blocks that model linear functions

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Discontinuities The Discontinuities

library contains blocks whose outputs are discontinuous functions of their inputs.

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Discrete The Discrete library

contains blocks that represent discrete-time functions.

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Math Operations The Math

Operations library contains blocks that model general mathematical functions.

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Math Operations More math

functions.

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Signal Routing The Signal Routing

library contains blocks that route signals from one point in a block diagram to another.

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Sink The Sinks library

contains blocks that display or write block output.

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Sources The Sources

library contains blocks that generate signals.

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SimPowerSystems Blockset It is library of

specialized blocks pertaining to Electrical Engineering.

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Electrical Drives using Simulink Electrical Machines:

(1)D.C.Machines(2)Asynchronous Machines(3) Synchronous Machines

and (4)Transformers models are available in

SimPowerSystems Blockset of Simulink.

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(1)D.C.Machines This block implements a

separately excited DC machine. An access is provided to the field

terminals (F+, F-) so that the machine model can be used as a shunt-connected or a series-connected DC machine.

The armature circuit (A+, A-) consist of an inductor La and resistor Ra in series with a counter-electromotive force (CEMF) E.

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D.C.Machines Machine data to be

entered is shown here.

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D.C.Machines Measurements are available through

demultiplexer. Four internal signals are multiplexed on the

Simulink measurement output vector returning

Rotor speed in rad/sec. Armature current in ‘A’ Field current in ‘A’ Electromechanical torque in ‘N.m’

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D.C.Machines Source D.C.Voltage source

Load Torque in (N-m). Constant Load can be implemented

by constant block of sources library

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D.C. Shunt Motor Drive

Fig. above shows D.C.Shunt motor drive with constant load.

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Transient response.

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D.C.Series Motor Drive

Fig. above shows D.C.Series motor drive with constant load.

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Transient response.

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(2)Asynchronous Machines (Induction Machines) This block implements an

Induction machine. The Asynchronous Machine

block operates in either generating or motoring mode.

The mode of operation is dictated by the sign of the mechanical torque (positive for motoring, negative for generating).

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(2)Asynchronous Machines (Induction Machines) The parameters to

be entered are shown here.

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Induction Machines Measurements are

available through Machine Measurement Demux block located in ‘Machines’ library of SimPowerSystems Blockset.

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Induction Machines

AC voltage source

Single phase and three phase AC sources are available, voltage and frequency of which can be adjusted as per requirement.

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Induction Machines Drive

Fig. above shows an Induction motor with constant load

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Induction Machines Drive

Transient response

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Types of Loads

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Fig. above shows D.C.Series motor drive with Load torque proportional to speed.

LT

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Transient response.

TL

TM

LT

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Fig. above shows D.C.Series motor drive with Load torque proportional to square of speed.

2LT

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TL

2LT

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Speed Control

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DC Shunt Motor

Armature voltage control method

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DC Shunt Motor

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DC Shunt Motor

Field flux control method

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DC Shunt Motor

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DC Series Motor

Field diverter method

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DC Series Motor

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Induction Motor

Stator voltage control method

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Induction Motor

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Induction Motor

Stator supply frequency control method

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Braking of Motors

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DC Shunt Motor

Regenerative braking of dc shunt motor

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DC Shunt Motor

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DC Shunt Motor

Regenerative braking of dc shunt motor

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Induction Motor

Regenerative braking of Induction motor

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Induction Motor

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Induction Motor

Regenerative braking of Induction motor

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Power Modulators

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Block diagram of an electric drive

Source Powermodulator

Motor Load

Sensingunit

Controlunit

Input command

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Power Modulator

Power modulator performs following four functions

Modulated flow of power from source to motor

Restricts source and motor currents within limits

Converts source energy suitable to motor Selects mode of operation i.e motoring or

braking

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AC to DC converters

Fixed voltage1ph or 3-ph

ac

Fixed voltagedc

Diode rectifier

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AC to DC converters

Single phase Diode rectifier using universal bridge

2 mdc

VV

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AC-DC converters

Single phase diode rectifier wave forms

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DC Shunt Motor fed with 1ph-diode rectifier

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AC to DC converters


ac

Variable voltagedc

Fully controlled thyristor rectifier

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AC to DC converters

Fully controlled thyristor rectifier using universal bridge

2cosm

dc

VV

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AC-DC converters

Fully controlled thyristor rectifier wave forms

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DC Shunt Motor fed with 1ph-controlled rectifier

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Triggering of 1ph-controlled rectifier

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AC Voltage Controllers


acDiode rectifier


ac

Variable voltageac

Thyristor voltage controller

(Soft starters)

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Soft starter

78(Available as demo)

Soft starter

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Soft started Induction motor drive

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DC-DC converters (Choppers)

Diode rectifier

Fixed voltagedc

Variable voltagedc

Semiconductorchopper

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Chopper fed DC drive

(Available as demo)

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AC Voltage Controllers

Fixed voltagedc

Diode rectifier

Variable frequencyFixed voltage

acStepped waveSemiconductor

inverter

(Soft starters)Diode rectifierPWM semiconductorinverter

Fixed voltagedc

Variable frequencyVariable voltage

ac

(a)

(b)

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PWM inverter

PWM inverter using universal bridge

2 2dc

ac

VV m

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Induction Motor drive usingPWM inverter


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Generation of PWM pulses


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Generation of PWM pulses

PWM pulses to inverter

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Output voltage of PWM inverter


drives using simulink

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