seminar on phase controlled converters & it's application in dc drives with closed loop...
TRANSCRIPT
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Seminar OnSeminar OnPhase Controlled Converters
and it’s applications In D.C. drives
Presented By Debraj Rakshit M.Tech (Power Electronics & Drives) Jalpaiguri Govt Engg. College
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What is Rectifier?• Definition:-Converting a.c.(from
mains or other a.c. sources) to d.c. power by
power diodes or by controlling the firing angle of thyristors/controllable switches.
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Types of Types of rectifiersrectifiers
• Uncontrolled Rectifiers
• Semi controlled Rectifiers
• Controlled Rectifiers
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Uncontrolled Rectifiers with R-load
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Uncontrolled rectifier with R-L-load
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Controlled half wave with R-load
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Uncontrolled full wave rectifier with R-load
• Bridge Configuration • Center Tapped Configuration• For both Configuration
• Vo ={VmSin ωt 0 ≤ ω t ≤ π
={-VmSin ωt π ≤ ω t ≤ 2 π
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Bridge Rectifier with R-Load
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Bridge Rectifier with R-L-load
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Vector Diagram of three phase supply voltage
V A N
V C N
V B N
1 2 00
1 2 00
1 2 00
RN AN
YN BN
BN CN
v v
v v
v v
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Three phase half wave converter with R-L load
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Necessary waveforms for three phase half wave
circuit
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Output voltage for various triggering angle
0
0
3 00
3 00
6 00
6 00
9 00
9 00
1 2 00
1 2 00
1 5 00
1 5 00
1 8 00
1 8 00
2 1 00
2 1 00
2 4 00
2 4 00
2 7 00
2 7 00
3 0 00
3 0 00
3 3 00
3 3 00
3 6 00
3 6 00
3 9 00
3 9 00
4 2 00
4 2 00
V an
V 0
V 0
V an
= 300
= 600
V bn
V bn
V cn
V cn
t
t
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Three phase full converter with R-L-load
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Waveforms for three phase full converter
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An Introduction to d.c. drives
• Definition:-An electric drive can be defined as an electromechanical device for converting electrical energy into mechanical energy for various kinds of process control.
• Classification of Drives:-• Group Electric Drive• Individual Electric Drive• Multimotor Electric Drive
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An Introduction to Closed Loop Control Of D.C.
drives• Closed loop System-Closed loop system
utilizes feedback to measure the actual system operating parameter being controlled such as temp,pressure etc.
• Open loop system-In Open loop control no feedback loop is employed and system
variations which cause the output to deviate from the desired value are not detected or corrected.
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Basic Block diagram of a closed loop speed control
system
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Essential parts of d.c. motor
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An introduction to closed loop control of separately excited d.c. motor
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Possible methods of speed control
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Introduction to dynamic equations and small
signal model of motor
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Small signal model of separately excited d.c.
motor
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Speed Control Loop
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Current Control Loop
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Proportional control to step change in speed
reference
Speed Response
Current Response
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Response of PI Control To Step Change in Speed
Reference
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Effect of Load Torque Disturbance
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Response to Step increasing load torque in
proportional control
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Response to step increase in load torque
with PI Control
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Linearized Model of dc series motor
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PLL based motor speed control
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Future Analysis Power Circuit of proposed QRZCS DC Drive
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Thank YouReferences
Power Electronics (M.H.Rashid)
Power Electronics (Khanchandani & Singh)
Thyristor Based DC Drive By P.C. Sen http://ieeexplore.ieee.org www.books.google.com www.en.wikipedia.org