1 Institute of Mechatronics and Information Systems Control and Driving Systems

1

Institute of Mechatronics and Information Systems

Control and Driving Systems

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Lecture programme:

1. Fundamentals of electromagnetic phenomena in electro-mechanic energy conversion

2. Structure and operating principle of modern electrical machines used in driving systems

3. Power supplies – voltage and frequency converters 4. Control modes for chosen mechanical drive parameters 5. Parasitic phenomena 6. Advantages and disadvantages of various driving system

configurations

3


Structure and operating principle of modern electrical machines used in driving systems

1. Transformer2. Direct current machine3. Induction machine4. Synchronous machine5. Special configurations

4


Induction (asynchronous) machine

5



Rotor (armature) types

6



Three phase magnetic field excitation

7



Rotating magnetic field

8



Ferro-magnetic core cross-section (lamination)

9



Stator (field) winding

10



Three phase magnetic field excitation

11



Synchronous speed:

Rotor speed:

Slip:

pf

ns

s1nn s

s

s

nnn

s

12



Equivalent circuit

sR

FeRs

s1Rrs

rsRsX rsX

mXphU phE

13



Electromagnetic torque:

2rss

2

rss

rs

2

m

s

2ph

s

sem

XXs

RR

sR

XX

1

U

n2m

M

14



Electromagnetic torque:

15


Induction (asynchronous) machineBasic characteristics

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

0 0,2 0,4 0,6 0,8 1

M/MN [-]

x/x

N [

-]

n

cosφ

η

I

16



Simplified equations Electromagnetic torque:

Breakdown (maximal) torque:

Breakdown slip:

2rss

2

rs

rs

2ph

s

sem

XXs

Rs

R

Un2

mM

rss

2ph

s

sb XX2

1U

n2m

M

rss

rsb XX

Rs

17



Simplified equations Electromagnetic torque, Kloss equation:

therefore starting torque:

Overload coefficient:

ss

ss

M2M

b

b

bem

bb

b1

ss1

M2M

N

bNbN M

Mm

18


Induction (asynchronous) machineLoad torque versus electromagnetic torque

0

0,5

1

1,5

2

2,5

0 0,2 0,4 0,6 0,8 1

n/nsN [-]

M/M

N [

-]

19


Induction (asynchronous) machineStart-up

0

1

2

3

4

5

6

7

8

9

10

0 2 4 6 8 10 12

time [s]

rati

o [

-] current

speed

20


Induction slip ring machine

Modification of output characteristics

rss

rsb XX

Rs

21




22




brake motor generator

23


Induction squirrel cage machine

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25



Modification of output characteristicsDahlander winding setup

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Modification of output characteristics Frequency and voltage converter

rectifier inverterDC link

27



Simplified equations Electromagnetic torque:


Breakdown slip:

2rss

2

rs

rs

2ph

s

sem

XXs

Rs

R

Un2

mM

rss

2ph

s

sb XX2

1U

n2m

M

rss

rsb XX

Rs

28



Modification of output characteristics Electromagnetic dependencies:


Breakdown slip:

.const f

U

f

U .const

N fS 2

UB

N

phNph

Fe

phm

2

N

phN

ph

bN

b

ff

U

U

MM

ff

ss N

bN

b

29


Induction (asynchronous) machineModification of output characteristics Varying frequency and voltage – constant Bm

30



Modification of output characteristics Varying frequency and constant voltage

0

0,5

1

1,5

2

2,5

0 0,5 1 1,5 2

f/fN [-]

M/M

N [

-]

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Modification of output characteristics Control limitations

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

1,8

2

0 0,5 1 1,5 2

f/fN [-]

x/x

N [

-]

n

U

M

Mb

32



Losses and efficiency (Sankey diagram)

s FeP

cosUI3Pin

emPMPout

s2phsRI3

r2pfrRI3 r FeP .frictP .ventP

33


Thank You for Your attention

Documents

1 Institute of Mechatronics and Information Systems Control and Driving Systems