Vfd Training 2p3kv
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Transcript of Vfd Training 2p3kv
POWER MODULES FOR VFD
VARIABLE FREQUENCY DRIVES
(VFD)
POWER MODULES FOR VFD
Introduction
• Variable Frequency Drives (VFD) are
used for speed control of AC motors
• Load Commutated Inverters ( LCI)
concept used for controlling
Synchronous Motor
POWER MODULES FOR VFD
FEATURES OF LCI
1. Speed control of Synchronous motor
2. Provides smooth speed control
3. Fuse less design
4. Thyristors are used as switching device
POWER MODULES FOR VFD
RATINGS
a. 1.2 kV modules
b. 2.3 kV modules
c. 4.2 kV modules
Generally 1.2 kV modules are used in
210 MW boilers, 2.3 kV for 500 MW
boilers.
POWER MODULES FOR VFD
Configuration:
Source side converter consists of 6 power modules in 3 phase bridge configuration to get DC.
Load side converter consists of 6 power modules in 3 phase bridge configuration to get Variable Frequency Variable Voltage
POWER MODULES FOR VFD
Power module consists of :
a. Thyristors as switching device
b. Heatsinks to dissipate heat generated in device
c. Snubber resistor and capacitor to protect device against overvoltages
d. Sharing resistors for equalising the voltage across series connected thyristors.
e. Pulse transformer to supply gate pulses to thyristor and to provide isolation between control and power circuit.
POWER MODULES FOR VFD
Construction:
1.2 kV module• Two thyristors are used in series.• Snubber provides protection to thyristor against
over voltages.• Reactor limits rate of rise of On state current• HPTF module gives firing pulses to thyristors
and also indicates healthiness of thyristors.
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
anode+
cathode-
p1 n1 p2 n2
J1 J2 J3
Ig
Three-terminal thyristor:
POWER MODULES FOR VFD
POWER MODULES FOR VFD
Transient V I characteristics of Thyristor
POWER MODULES FOR VFD
Three-terminal thyristor:
0-1: Forward blocking / OFF state J1,J3: forward, J2: reversed biased 2-3: Forward conduction / ON state J1, J2, J3: Forward biased0-4: Reversed biased J1,J3: reverse, J2: forward biased 4-5: Breakdown
OFF
ON
anode+
cathode-
p1 n1 p2 n2
J1 J2 J3
switching (dV/dI=0)
forward break-over voltage
holding voltage
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
General mounting arrangement
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
Thyristor stack : 1.2 kV
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
HPTF module
POWER MODULES FOR VFD
Construction:
2.3 kV module • Three thyristors are used in series.• Snubber provides protection to thyristor against
over voltages.• HPTK module gives firing pulses and indicates
healthiness of thyristors.• NTDA module indicates healthiness of thyristors• XPTN module gives attenuated voltage for
control
POWER MODULES FOR VFD
POWER MODULE 2.3 kV
POWER MODULES FOR VFD
THYRISTOR STACK 2.3 kV
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
Snubber : 2.3 kV
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
HPTK module
POWER MODULES FOR VFD
POWER MODULES FOR VFD
XPTN Module
POWER MODULES FOR VFD
Synchronous Field Exciter module
Features:• Six thyristors in ac controller configuration.• Snubber provides protection to thyristor against
over voltages.• NHVL module gives firing pulses to thyristors
and also indicates thyristor healthiness• Voltage attenuator and current feedback
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
POWER MODULES FOR VFD
Field Exciter Module
POWER MODULES FOR VFD
POWER MODULES FOR VFD
THANK YOU