Ppt 6. Solid State Control - Large Fonts
-
Upload
anuradha-ska -
Category
Documents
-
view
217 -
download
0
Transcript of Ppt 6. Solid State Control - Large Fonts
![Page 1: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/1.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 1/34
Solid State Control Applied Electricity – EE 2802
![Page 2: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/2.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 2/34
![Page 3: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/3.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 3/34
Power Switching Devices
Power diode
Power transistor
Silicon controlled rectifier (SCR)
Gate turn-off thyristor (GTO)
MOSFET
Insulated gate bipolar transistor
![Page 4: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/4.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 4/34
Motor Drive
A modern variable speed system has
four components:
1. Electric machine
2. Power converter
3. Controller4. Load
![Page 5: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/5.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 5/34
Closed Loop Speed Control
![Page 6: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/6.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 6/34
Speed Control of DC Motors
![Page 7: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/7.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 7/34
Methods
1. Field control2. Armature control
Armature resistance control
Armature voltage control
![Page 8: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/8.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 8/34
Field Control
Speed variation is possible only
above the rated speed
Armature Control
Only below the rated speed
![Page 9: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/9.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 9/34
Armature & Field Control
By combining armature and field control
-> a wide range of speed control is
possible
![Page 10: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/10.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 10/34
Four Quadrant Operation
Operating in both directions of rotation
Producing both motoring and
regeneration
![Page 11: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/11.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 11/34
V lt & t
![Page 12: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/12.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 12/34
Voltage & urrentRequirement for 4Q
Operation Assuming filed flux is constant, speed is
approximately proportional to applied
voltage
Speed axis becomes the armature
voltage axis
Torque is proportional to armature
current
Torque axis becomes the armature
![Page 13: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/13.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 13/34
Operation
Speed Torque Voltage Current
Power
Output
Forward
Motoring
+ + + + +
ForwardRegeneration
+ - + - -
Reverse
Motoring
- - - - +
Reverse
Regeneration
- + - + -
![Page 14: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/14.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 14/34
Variable Voltage & Variable
Current DC Output
1. Phase controlled rectifiers
2. Diode bridge rectifiers with choppers
![Page 15: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/15.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 15/34
1. Phase controlled rectifiers
Converts AC source voltage directly
into a variable DC voltage
2. Chopper controlled converters
Converts Fixed DC to a variable DC
voltage
![Page 16: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/16.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 16/34
1) Phase Controlled Converters
Use Thyristors …….
Thyristor/SCR (Silicon Controlled
Rectifier)
Terminals anode, cathode and gate
To turn ON, a gate current should beinjected when anode is (+)ve comparedto cathode
After turning ON, the thyristor acts like a
diode
![Page 17: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/17.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 17/34
![Page 18: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/18.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 18/34
4Q Operation
![Page 19: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/19.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 19/34
How it works?Example : Single-Phase Controlled Converter
Conduction can be delayed beyond zerocrossing
Delay is introduced in the form oftriggering signals to the gates
![Page 20: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/20.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 20/34
![Page 21: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/21.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 21/34
Inversion
Increase delay angle > 900
Produce a (-) ve average voltage
Load current is in the same direction
Contribute to a (-) ve power input
![Page 22: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/22.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 22/34
2) Chopper Controlled DC
Motor Drives
Used when the source is a constant
voltage DC
- battery or- diode bridge rectified AC
supply
Chopper circuit converts fixed voltage
into a variable voltage
![Page 23: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/23.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 23/34
Speed Control of ACInduction Motors
![Page 24: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/24.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 24/34
Methods
1. Changing the no. of poles- limited control
- only several steps of speed is
possible
2. Slip control
◦
Varying applied voltage◦ Adding external resistance
3. Frequency control
![Page 25: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/25.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 25/34
1. Phase controlled IM drives
1. Stator voltage control
2. Slip energy recovery scheme
2. Frequency controlled IM drives
3. Vector controlled IM drives
![Page 26: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/26.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 26/34
1. Phase Controlled IM
Drives1. Stator Voltage Control
Efficiency is very low
Quite similar to 3-phase controlled
bridge converter used in DC motors
![Page 27: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/27.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 27/34
2. Slip Energy Recovery Scheme
Efficiency is improved by slip energy
recovery
As speed decreases rotor copper loss
increases -> reduce the efficiency
Here the slip energy is sent back to
the AC supply using an external emf
![Page 28: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/28.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 28/34
![Page 29: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/29.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 29/34
2. Freq. Controlled IM Drives
Utility supply is having constant
frequency
Need a frequency changer
1. Direct Frequency Changer
2. Indirect Frequency Changer
![Page 30: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/30.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 30/34
Direct Frequency Changers
Small range of frequency variation Suitable for low speed large power
applications
![Page 31: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/31.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 31/34
Indirect Frequency Changers
Wide range of frequency variation
Consists of
- a rectification (AC to DC) and
- an inversion (DC to AC)
Cannot be used for regeneration
![Page 32: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/32.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 32/34
For Regeneration
![Page 33: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/33.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 33/34
3. Vector Controlled IM
Drives Previous methods provide good steady
state responses
Poor dynamic responses
- due to deviation in air gap flux
linkage
- in magnitude and phase
Vector control is used to control this
variation
![Page 34: Ppt 6. Solid State Control - Large Fonts](https://reader030.fdocuments.in/reader030/viewer/2022021320/577cc3171a28aba7119517cb/html5/thumbnails/34.jpg)
8/10/2019 Ppt 6. Solid State Control - Large Fonts
http://slidepdf.com/reader/full/ppt-6-solid-state-control-large-fonts 34/34
Reference
Electric Motor Drives
Modeling, Analysis, and Control
R. Krishnan