MODELING AND SIMULATION OF DYNAMIC SYSTEMS

MIXED DISCIPLINE SYSTEMS

PHAM HUY HOANG HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY

INTRODUCTION

MIXED DISCIPLINE SYSTEM:

MIXED DISCIPLINE SYSTEM – COUPLING SYSTEM OF

SINGLE-DISCIPLINE SYSTEMS

Pham Huy Hoang

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ELECTROMECHANICAL SYSTEMS

-

-

ARMATURE-CONTROLLED DC MOTOR Voltage is electric potential energy per unit charge (J/C = V) - referred to as "electric potential”. Electromotive force (emf) voltage (electromotance): is that which tends to cause current (actual - electrons and ions) to flow; is the external work expended per unit of charge to produce an electric potential difference across two open-circuited terminals; is generated by a magnetic force (Faraday’s law).

Pham Huy Hoang

ELECTROMECHANICAL SYSTEMS

Faraday's Law Any change in the magnetic environment* of a coil of wire will cause a voltage (emf) to be "induced" in the coil. * The change of magnetic field strength, relative displacement between the magnet field and the coil.

Pham Huy Hoang

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Pham Huy Hoang

ELECTROMECHANICAL SYSTEMS

The back emf voltage across a DC motor:

=

=

K

K

e b

w e

& q e

The torque developed by the motor:

= iKT t

q =&

: angular velocity of the rotor

eb : back emf voltage. q : angular displacement of the rotor of the motor w T : torque applied to the rotor Ke : emf constant (Vs/rad) Ki : torque constant (Nm/A)

Pham Huy Hoang

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ELECTROMECHANICAL SYSTEMS

aL

w

=&, qq

aR

ai

LT

rJ

dJ

be

aV

dB

+

+

=

v

v

0

e b

v a

aR

aL

-

+

+

=

iR aa

L a

e b

v a

=

di a dt = K

K

& q e

e b

w e

+

+

=

K

)1(

iR aa

L a

& q e

v a

di a dt

Pham Huy Hoang

ELECTROMECHANICAL SYSTEMS

aL

w

=&, qq

aR

ai

LT

rJ

dJ

be

aV

dB

r

d & q

= + J J J

= - && q J B d

& q = - && q J )2( + TT L = iKT at + T L iK at B d

Pham Huy Hoang

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ELECTROMECHANICAL SYSTEMS

aL

aR

ai

LT

rJ

dJ

be

aV

dB

w =&, qq

+ & q = - && q J B d iK at T L

+ + = K iR aa & q e v a L a di a dt

t

e

- 0 0 K + + = B d K 0 J 0 00                         L a R a q   i  a T  L  v  a         && q    ..  i a & q    .  i a

Pham Huy Hoang

ELECTROMECHANICAL SYSTEMS

aL

w

=&, qq

aR

ai

LT

dJ

be

aV

rJ BK,

dB

Pham Huy Hoang

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ELECTROMECHANICAL SYSTEMS

FIELD-CONTROLLED DC MOTOR

w

fR

=&, qq

=

const

ia

LT

fi

rJ

fv

dJ

fL

dB

0=

be

ftiKT =

di

+

=

L

v

)1(

iR f

f

f

f

f dt

Pham Huy Hoang

ELECTROMECHANICAL SYSTEMS

w

fR

=&, qq

=

const

ia

LT

fi

rJ

fv

dJ

fL

dB

0=

be

ftiKT =

=

+

J

J

J

r

d & q

=

&& q J

B d

+ TT L = iKT ft +

& q

=

-

&& q J

)2(

iK ft

T L

B d

-

Pham Huy Hoang

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ELECTROMECHANICAL SYSTEMS

w

fR

=&, qq

=

const

ia

LT

fi

rJ

fv

dJ

fL

dB

0=

be

ftiKT =

+

=

& q

&& q J

fitK

LT

+

=

fv

fL

dB fdi dt

-

+

=

J 0

dB 0

tK fR

0 fL

  

  

  

  

 LT  fv 

  

& q   fi 

  

fifR && q    .  fi

   

-

Pham Huy Hoang

ELECTROMECHANICAL SYSTEMS

w

fR

=&, qq

=

const

ia

LT

fi

rJ

fv

dJ

fL

dB

0=

be

ftiKT =

Pham Huy Hoang

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ELECTROMECHANICAL SYSTEMS

MAGNETO-ELECTRO-MECHANICAL SYSTEMS

Lenz’s law: increasing current in a coil will generate a counter emf which opposes the current. (The emf always opposes the change in current).

The relation of this counter emf to the current is the origin of the concept of inductance.

Pham Huy Hoang

ELECTROMECHANICAL SYSTEMS

Magnetic Force and Lorentz force law: - The force is perpendicular to both the velocity v of the charge q and the magnetic field B (N/A = Ns/C = Tesla). - The magnitude of the force is F = qvB sinθ (θ is the angle between the velocity and the magnetic field).

Pham Huy Hoang

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ELECTROMECHANICAL SYSTEMS

-The magnetic force on a stationary charge or a charge moving parallel to the magnetic field is zero. - The direction of the force is given by the right hand rule.

Pham Huy Hoang

ELECTROMECHANICAL SYSTEMS

2i

1i

2R

1R

L

v

C

1k

1c

b

1m

y

1x

a

2k

2c

Magnetic force :

2m

2x

Electromot ive iK 21 ( force emf :) &2 yK

Pham Huy Hoang

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ELECTROMECHANICAL SYSTEMS

2i

1i

2R

1R

v

L

C

y

a

+

=

dt

v

iR 11

i dt 1

i 2

1 C

1 C

t ∫ 0

t ∫ 0

+

+

+

=

-

L

Kdt

0

i dt 1

iR 22

i 2

2

& x 1

1 C

di 2 dt

1 C

b a

t ∫ 0

t ∫ 0

- -

Pham Huy Hoang

ELECTROMECHANICAL SYSTEMS

=

M

J

O

a O

2

+

+

+

(

[

k

(

)

(

)]

aiK 21

xk 11

& bxc ) 11

x 2

2

x 1

c 2

& x 2

= & bmbx 1 1

  

  

&& x 1 b

2

2

+

+

+

=

+

- - - -

(

0

(

& xbc ) 1 2

2 & xbc 2 2

k 1

xbk ) 1 2

2 xbk 2 2

abiK 1 2

=

- -

& x 2

1k

1c

) +

) +

&& xm 22 =

- - - -

0

+ && xm c 11 1 ∑ = && xmF 22 ( k x x 2 1 2 && & xm xc 12 22

( c 2 & xc 22

& x 1 xk 12

xk 22

b

1m

1x

2k

2c

2m

2x

- -

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