Components of HVDC
description
Transcript of Components of HVDC
SPECIAL SPECIAL
COMPONENTS OF COMPONENTS OF
TALCHER – KOLAR TALCHER – KOLAR
BIPOLAR HVDC BIPOLAR HVDC
Lecture byLecture by
P.RANGA RAOP.RANGA RAO
Chief Manager / KolarChief Manager / Kolar
HVDC EQUIPMENTSHVDC EQUIPMENTS
What are the Special Components of HVDC?
1. Converter Transformer2. Valve Hall3. AC Harmonic Filters4. Shunt Capacitors 5. DC Harmonic Filters6. Smoothing Reactors7. DC Current / Voltage measuring devices8. Valve Cooling / Ventilation System9. Valve Timing PT10. VESDA11. Electrode Station12. Repeater Station
MAIN COMPONENTS OF HVDCMAIN COMPONENTS OF HVDC
Converter Xmers
Valve Hall
-Thyristors
Smoothing Reactor
Basic Components of HVDC TerminalBasic Components of HVDC Terminal
400 kV
DC Line
-Control & Protection
-Telecommunication
AC Shunt Capacitors
DC Filter
AC Harmonic filters
Valve Cooling / Ventilation system
Electrode station
CONVERTER TRANSFORMERCONVERTER TRANSFORMER
STAR BUSHINGS
400KV SIDE BUSHING
DELTA BUSHING
Converter TransformerConverter Transformer
CONVERTER TRANSFORMERSCONVERTER TRANSFORMERS
Three Singe Phase Transformers for each Pole Each Transformer is of Three Windings
Winding -1 connected to 400KV side in Star Winding -2 connected to one six pulse bridge in
Star Winding -3 connected to second six pulse bridge
in Delta Easy transportation
Automatic onload tap changer control with appropriate make and break capacity
Extra insulation due to DC currents Proper conductors and magnetic shunts to take
care of the extra losses due to harmonic currents Very rugged and reliable OLTC as tap-changing
is a integral means of conversion process and control.
FEATURES OF CONVERTER FEATURES OF CONVERTER TRANSFORMERSTRANSFORMERS
•Type of converter transformer : Single phase three windings
•Rated power of line / star / delta winding (MVA) : 397/198.5/198.5
•Rated current of line / star / delta winding (A): 1719/1635/944
•Rated Voltage of Line/star/delta winding (No-load): 400/√3/210.3/√3/210.3
•Tap changer (voltage range) : -5 % to +20 %•Tap changer steps : 16 to -4 (21 steps)•Tap changer current capacity : 2X2000A
•Cooling arrangement : ODAF
Converter Transformer RatingsConverter Transformer Ratings
No load losses – 192KW Load losses - 760KW @75°C Oil type – Napthanic, Shell Diala Bushings
Line side – oil filled Valve side – Y – SF6 filled Valve side – D – RIP condenser Total weight – 461 Ton Oil weight – 118.7 Ton
Converter Transformer RatingsConverter Transformer Ratings
Converter Transformer Connection Converter Transformer Connection
Y
Y
Y
D
D
D1-ph 3 winding
Converter Transformer
Valve Hall
Outdoor
RR
YY
BB
Converter Transformer Cooling control
Automatic daily changeover of cooling pumps and fans 5 groups of fans and pumps
Each group – One oil circulating pump & 3 cooling fans 4 groups will be in service with 2 fans each One redundant group – changeovers every day Extra fans will switch ON when winding temperature > 75ºC Redundant group will switch ON when winding temperature >85ºC WTI Alarm - 115ºC WTI Trip - 130ºC OTI Alarm - 85ºC OTI Trip - 95ºC
Converter Transformer internal connection
HVDC VALVE HALL LAYOUTHVDC VALVE HALL LAYOUT
Multiple Valve UnitMultiple Valve Unit
• Indoor type• Air insulation• Direct water cooling of all components in the valve producing losses• Application of single thyristors with a high current carrying and voltage
blocking capability (no parallel connection of thyristors)• Optoelectronic firing and monitoring system from the ground to thyristor
potential and vice versa without intermediate electronics• Monitoring of the status of all thyristor levels during operation• Protective firing of the thyristors as back up firing for self protection of
the valves against high over voltages in forward direction• Direct parallel connected surge arresters to each valve
Valve Hall Layout Cross SectionValve Hall Layout Cross Section
DC Bushing
Converter Transformer
Converter Valves
Valve Hall
Smoothing Rector
MULTIPLE VALVE UNIT
AC
DC
ValveQ uadrup leva lve
A rrester
AC
G rd
Multiple
Valve
Unit
DD
YYYY
Circuit Diagram of the Converters for Pole 1Circuit Diagram of the Converters for Pole 1
Valve Tower side view
1. AC Terminal2. DC Terminal3. Cooling Water Inlet4. Cooling Water Outlet5. Fiber Optic Cables Tubes
6. Thyristor Module7. Insulator8. Arrester9. Screen
• Max. length of fibre optic cables in quadruple valve Lmax = 17.5m• Weight of quadruple valve without arresters: approx. 19300 kg• All dimensions in mm
Valve Tower top view / 3D view
1. AC Terminal2. DC Terminal3. Cooling Water Inlet4. Cooling Water Outlet5. Fibre Optic Cables Tubes
6. Thyristor Module7. Insulator8. Arrester9. Screen
• Max. length of fibre optic cables in quadruple valve Lmax = 17.5m• Weight of quadruple valve without arresters: approx. 19300 kg• All dimensions in mm
Valve StructureValve Structure
Valve Section / tier Single Valve Quadra Valve
Hierarchy of Hierarchy of valve structurevalve structure
Each Thyristor level consistsEach Thyristor level consists
•ThyristorThyristor
•Snubber circuit – to prevent high Snubber circuit – to prevent high dv/dtdv/dt
•Snubber CapacitorSnubber Capacitor
•Snubber ResistorSnubber Resistor
•Valve Reactor – to prevent high Valve Reactor – to prevent high di/dtdi/dt
•Grading Resistor – to equilize the Grading Resistor – to equilize the potential across all the levels in a potential across all the levels in a valve – static equalizingvalve – static equalizing
•Grading capacitor – dynamic Grading capacitor – dynamic equalizing equalizing
Components in one valveComponents in one valve
Component Population at Talcher
Population at Kolar
Thyristor 84 78
Snubber Capacitor 84 78
Snubber Resistor 84 78
Valve Reactor 24 24
Grading Capacitor 6 6
Grading Resistor 84 78
Valve arrester 1 1
TE card 84 78
Component Population at Talcher
Population at Kolar
Thyristor 1008 936
Snubber Capacitor 1008 936
Snubber Resistor 1008 936
Valve Reactor 288 288
Grading Capacitor 72 72
Grading Resistor 1008 936
Valve arrester 144 144
TE card 1008 936
Components in one PoleComponents in one Pole
Thyristor Module
SNUBBER CAPACITOR
SNUBBER RESISTOR
THYRISTOR
TE CARD
COOLING PIPE-PEX
GRADING CAPACITOR
FIBRE OPTICS
Thyristor Modular Unit top view
Thyristor Modular Unit Detailed View of Thyristor Stack
Eastern Terminal (Talcher)
14 Thyristors
Southern Terminal (Kolar)
13 Thyristors
Thyristor Modular Unit Schematical Cooling Circuit
Eastern Terminal (Talcher)
14 Thyristors
Southern Terminal (Kolar)
13 Thyristors
Z = Cooling Water Inlet
A = Cooling Water Outlet
Composition of an HVDC Valve
T L =G ateu n it
H ea ts in ks+ + +
+
TL
TL
V S
V S
= + + +F ib re o p t ic
s yst emC oo lan td is t rib .
In su la tin gs t ru c tu re
= +V S
W h ere k= N o . o f t h yris to r level sin a va lve s ec tion
n = N o . o f th yr is to r le ve lsin a va lve
N ote V S is th e sm a lle stre p ea ta b le e lec t rica lu n i t o f a va lve,m ech an ica l s u b -u n itsm ay c on ta in m u lt ip leo r su b -d e vid ed va l ves ection s
T h yris to rle ve l
V a lvese ct ion
V a lve
1
k
1
nk
1 < k< n
Block Diagram of Thyristor ElectronicBlock Diagram of Thyristor Electronic
1 Light Receiver2 Light Transmitter3 Thyristor Voltage Detection4 Logic
5 Gate Pusle Amplifier6 Back Up Trigger Circuit (BTC)7 Energy Supply
Multi-Arm Fibre Optic Cable Used for MonitoringMulti-Arm Fibre Optic Cable Used for Monitoring
Receiver Side
Emitter Side
1 Protective sleeves in red colour2 7 continuous single fibre cables
3 Labelling with markers4 Designation on shrinking tube
Multi-Arm Fibre Optic Cable with Signal Mixing Used for Triggering
Receiver Side
Emitter Side
1 Protective sleeves in blue colour2 Fibre cables statistically mixed
3,5 Labelling with markers4 Designation on shrinking tube
Thyristor T1501 N75 T - S34 (1)
Features:• High-power thyristor for phase control• Ceramic insulation• Contacts copper, nickel plated• Anode, Cathode and gate pressure contacted• Inter digitised amplifying gate
Applications:• HVDC-Transmissions• Synchro- drivers• Reactive-power compensation• Controlled Rectifiers
Internal Structure of ThyristorInternal Structure of Thyristor
Thyristor T1501 N75 T - S34 (2) - Electrical Thyristor T1501 N75 T - S34 (2) - Electrical Maximum Ratings Maximum Ratings
• Repetitive peak off-state voltage VDRM = 7.5 kV at TVJ = +5°C...120°C
• Repetitive peak reverse voltage VRRM = 7.5 kV at TVJ = +5°C...120°C
• Non-repetitive peak off-state voltage VDSM = 8.0 kV at TVJ = +5°C...120°C
• Non-repetitive peak reverse voltage VRSM = 8.3 kV at TVJ = +5°C...120°C
• Surge-on state current ITSM = 22 kA at TVJ = +90°C, 50 Hz Sinus, VR
= 0 V
• Critical non-rep. rate of rise of di/dtcr = 160 A/µs at TVJ = +90°C, VD = VDRM
on-state current
• Critical rate of rise of on-state voltage dV/dtcr = 8600 V/µs at TVJ = +90°C
Thyristor T1501 N75 T - S34 (3) - Electrical Characteristic Ratings
• Off-state current ID = 500 mA at TVJ = +90°C, VD = VDRM
• Reverse current IR = 500 mA at TVJ = +90°C, VR = VRRM
• On-state voltage VT = 2.7 kV at TVJ = +90°C, ITM = 4000 A
(stat. 50%/90% value)
• Circuit-commuted recovery time tq = max. 800 µs at TVJ = +90°C, ITM = 4000 A
di/dt = -4 A/µs, VR = 100 VdV/dt = 100 V/µs, VD = 5000 V
• Gate trigger current IGT = 400 mA at TVJ = +25°C, VD = 12 V
• Gate trigger voltage VGT = 3 V at TVJ = +25°C, VD = 12 V
Thyristor T1501 N75 T - S34 (4) - Thermal and Mechanical Thyristor T1501 N75 T - S34 (4) - Thermal and Mechanical RatingsRatings
• Operating junction temp. range TVJ = +5°C...+120°C
• Storage temp. range Tstg = -50°C...+60°C
• Thermal resistance Rth JC = 0.0064 K/W
• Mounting force fm = 63 kN...91 kN
• Weight m = 3.9 kg
• Creepage distance dcreep = 49 mm
• Air distance dair = 20 mm
Valve Reactor - Electrical and Mechanical RatingsValve Reactor - Electrical and Mechanical Ratings
• Voltage-time area = 80mVs ±10%
• Saturated part of main inductance LH = 0.55 mH ±10%
• Reactor current ID max = 1270 A
Current and Voltage Characteristic of the Valve Reactor
Valve Reactor - Dimensional DrawingValve Reactor - Dimensional Drawing
Grading Capacitor - Electrical and Mechanical RatingsGrading Capacitor - Electrical and Mechanical Ratings
• Capacity C = 2.4 µF ±3%
• Nominal voltage UN = 58 kV
• Periodical max. voltage Umax = 88 kV
• Short time max. impulse voltage Us = 8700 V
• Nominal effective current IN = 1 A
• Periodical max. current Imax = 100 A
• Operating frequency f = 50/60 Hz
• Cooling type self-cooling
• Weight approx. 25 kg
• Impregnation SF6 gas
Grading Capacitor - Dimensional Drawing
Snubber Circuit ResistorSnubber Circuit Resistor
Resistance R 45
Tolerance ± 3%
Cooling Water
Snubber Circuit CapacitorSnubber Circuit Capacitor
X
View X
Capacitance 1.6 µFd
Tolerance +/-5%
Insulation SF6
DC Smoothing ReactorsDC Smoothing Reactors
Smoothing Reactor - PurposeSmoothing Reactor - Purpose
Connected in series in each converter with each pole
Decreases harmonic voltages and currents in the DC line
Smooth the ripple in the DC current and prevents the current from becoming discontinuous at light loads
Limits crest current (di/dt) in the rectifier due to a short circuit on DC line
Limits current in the bypass valve firing due to the discharge of the shunt capacitances of the dc line
•Two Smoothing Reactors per pole
•Inductance - 125mH
•Nominal DC Voltage – 500KV
•Max DC Voltage – 515KV
•BIL – 950/1425KV
DC Smoothing Reactor ratingsDC Smoothing Reactor ratings
•Continuous current - 2000A
•Continuous Over load current - 2200A
•Type – Air Cored Dry type
•Natural Air Cooled reactors
•Location : Outdoor
•Total mass – 30 Ton
•Temperature Class - F
DC Smoothing Reactor ratingsDC Smoothing Reactor ratings
HARMONIC FILTERSHARMONIC FILTERS
Conversion process generates – Harmonics AC side Harmonics- Current harmonics
Generated harmonics – (12n ± 1) harmonics n = 1,2,3…. Predominant harmonics – 11,13,23,25,35,37 Additionally 3rd harmonics
DC side Harmonics- Voltage harmonics Generated harmonics – (12n) harmonics n = 1,2,3…. Predominant harmonics – 12,24,36
Disadvantages of Harmonics
Over heating and extra losses in generators Over heating and extra losses in motors Instability in the converter control Interference with telecommunication systems Over voltages due to resonance
AC Filters AC Filters - - KolarKolar
ITEM A B C
Filter sub bank DT 12/24 DT 3/36 Shunt C
Rating (3 ph., 400 kV) MVAr 120 97 138
No.of 3 phase Banks - 6 3 5
HV-Capacitor C1 μF 2.374 1.85 2.744
HV-Reactor L1 mH 16.208 5.444 1.602
HV-Resistor R1 ohms 420 300 -
LV-Capacitor C2 μF 4.503 3.759 -
LV-Reactor L2 mH 7.751 204.2 -
LV-Resistor R2 ohms - 1500 -
12/24 Double Tuned Filter – 120 MVAr12/24 Double Tuned Filter – 120 MVAr
C2=4.503 µF
R1=420Ω
L2=7.751mH
L1=16.208mH
C1=2.374µF
11 13 23 25
Impedance Graph
Capacitor Stack
ResistorReactorReactor
12/24 Double Tuned Filter – Sectional view12/24 Double Tuned Filter – Sectional view
CT
3/36 Double Tuned Filter – 97 MVAr3/36 Double Tuned Filter – 97 MVAr
C1=1.85µF
R1=300ΩL1=15.444 mH
C=23.759µFR2=1500 Ω
L2=204.2mH 3 35 37
Impedance Graph
Capacitor stack
ResistorReactor
C=23.759µF
Reactor
3/36 Double Tuned Filter – Sectional view3/36 Double Tuned Filter – Sectional view
CT
Shunt Capacitor – 138 MVArShunt Capacitor – 138 MVAr
C1=2.744 µF
L1=1.602 mH
•No harmonic filteringNo harmonic filtering
•Supplies MVAr to the gridSupplies MVAr to the grid
•Switched into the circuit for Switched into the circuit for voltage control purposevoltage control purpose
•Capacity – 138 MVArCapacity – 138 MVAr
Shunt Capacitors-Voltage ImprovementShunt Capacitors-Voltage Improvement
Ratings of Capacitors C1 & C2 of 12/24 filter Ratings of Capacitors C1 & C2 of 12/24 filter
Type 96 TILP 8 TILR
Make NOKIAN NOKIAN
Capacitor Bank Rating
Capacitance ( per ph ) 2.37 F 4.50 F
Capacitor Bank 1 phase output 67.4 Mvar 0.94 Mvar
Capacitor Bank Voltages 301 kV 25.5 kV
Capacitor bank currents ( 1 ph ) 290 A 404 A
System Frequency 50 Hz 50 Hz
Electrical connections:
No. of units in series (s) 32 4
No of units in parallel 2+1 2
Total Units (1 ph ) 96 8
Capacitor Units
Unit Capacitance 25.3 F 8.99 F
Capacitor Unit rated output 703 Kvar 115 Kvar
Capacitor unit rated voltage 9406 Volts 6380 Volts
Capacitor Unit rated current 74.7 A 18 A
Type : EKE/ KLK Resistor DT 12/24 R1
Make : KLK Electro Materials, Spain Resistor material : Stainless Steel Ni-Cr 40 Cooling : Natural Air Temperature Coefficient of resistance : C = 0,00054u / OC Resistance (at nominal current) : 420 ohm MCOV -HV to Ground : 35 kV BIL/ SIL : 325/250 kV Total Losses : 678 kW/356 kW Max. temperature rise for the resistor element: t = 170 °C Inductance : L < 10320 H Thermal Time constant : 400 s Fundamental frequency : 50 Hz Weight : 450 kg
Ratings of Resistor of 12/24 filterRatings of Resistor of 12/24 filter
Type Dry, Air core Dry, Air core
Make Trench Limited, Canada
Trench Limited, Canada
Nominal Inductance mH 16.208 7.751
Tolerance on Inductance % +/-0.5 +/-1.0
Nominal Frequency Hz 50 50
Continuous Current ratingFundamentalMajor harmonicGeometric sum of Harmonic CurrentTotal Current Stress
AmpsAmpsAmps
Amps
180151.7 ( 11th )223
287
180241.3 ( 11th )366
408
BIL/ SIL (HV to LV)BIL/ SIL (HV to Ground)BIL/ SIL (LV to Ground)
kVkVkV
325/250325/250150/150
150/150150/150 95/95
Ratings of Reactors L1 & L2 of 12/24 filterRatings of Reactors L1 & L2 of 12/24 filter
Type 90 TILP 4TILR
Make NOKIAN NOKIAN
Capacitor Bank Rating
Capacitance (ph) 1.85 F 2.85 F
Capacitor Bank 1 phase output 48.2 Mvar 0.74 Mvar
Capacitor Bank Voltages 288 kV 25 kV
Capacitor bank currents ( 1 ph ) 180 A 75 A
System Frequency 50 Hz 50 Hz
Electrical connections:
No. of units in series (s) 30 4
No of units in parallel 2+1 1
Total Units (1 ph ) 90 4
Capacitor Units
Unit Capacitance 18.5 F 11.4 F
Capacitor Unit rated output 536 KVAr 151 KVAr
Capacitor unit rated voltage 9600 Volts 6500 Volts
Capacitor Unit rated current 55.8 A 23.3 A
Ratings of Capacitors C1 & C2 of 3/36 filterRatings of Capacitors C1 & C2 of 3/36 filter
Type : EKE/ KLK Resistor (DT 3/36 R1 )Make : KLK Electro Materials, (Spain)Resistor material : Stainless Steel Ni-Cr 40Cooling : Natural AirTemperature Coefficient of resistance : C = 0,00054u / OCResistance (at nominal current) : 420 ohmMCOV -HV to Ground : 35 kVBIL/ SIL : 325/250 kVTotal Losses : 678 kW/356 kWMax. Temperature rise for the resistor element: t = 170 °C Impulse energy at warm resistor : 230 kJInductance : L < 10320 HThermal Time constant : 400 sFundamental frequency : 50 HzWeight : 450 kg
Ratings of Resistor of 3/36 filterRatings of Resistor of 3/36 filter
Type Dry, Air core Dry, Air core
Make Trench Limited, Canada
Trench Limited, Canada
Nominal Inductance mH 5.444 204.2
Tolerance on Inductance % +/-0.5 +/-1.0
Nominal Frequency Hz 50 50
Continuous Current rating
FundamentalMajor harmonicGeometric sum of Harmonic
CurrentTotal Current Stress
AmpsAmpsAmps
Amps
16743.2 ( 13th )66
180
18123.3 (13th )24
183
BIL/ SIL (HV to LV)BIL/ SIL (HV to Ground)BIL/ SIL (LV to Ground)
kVkVkV
325/250325/250250/250
250/250250/25095/95
Ratings of Reactors L1 & L2 of 3/36 filterRatings of Reactors L1 & L2 of 3/36 filter
Type 96 TILP (138 Mvar)
Make BHEL
Capacitor Bank Rating
Capacitance ( ph ) 2.744 F (+/- 1%)
Capacitor Bank 1 phase output 63.8 Mvar
Capacitor Bank Voltages 272kV
Capacitor bank currents ( 1 ph ) 234.4 A
System Frequency 50 Hz
Electrical connections:
No. of units in series (s) 38
No of units in parallel 4
Total Units (1 ph ) 152
Capacitor Units
Unit Capacitance 26.07 F
Capacitor Unit rated output 419.6 Kvar
Capacitor unit rated voltage 7.16 kV
Capacitor Unit rated current 58.6 A
Ratings of Capacitors in Shunt CRatings of Capacitors in Shunt C
Type Dry, Air core
Make Trench Limited,
Canada
Nominal Inductance mH 1.602
Tolerance on Inductance % +/-1.5
Nominal Frequency Hz 50
Continuous Current ratingFundamentalMajor harmonicGeometric sum of Harmonic CurrentTotal Current Stress
AmpsAmpsAmpsAmps
23249.6 13th )78245
BIL/ SIL (HV to LV)BIL/ SIL (HV to Ground)BIL/ SIL (LV to Ground)
kVkVkV
325/250325/25095/95
Ratings of Reactors in Shunt CRatings of Reactors in Shunt C
DC FilterDC Filter 12/24 TYPE12/24 TYPE
C1=1800 nF
R1=400 ΩL1=14.71 mH
L2=8.19 mH
C1=5700 nF
Make ABB ABB
Nominal Capacitance nF 1800 5700
Tolerance of Nominal Capacitance % +/- 0.5 +/-1.0
Maximum DC VoltageArithmetic sum of Harmonic VoltageTotal Voltage Stress
kVkVkV
53859621
-5.37.5
Geometric sum of Harmonic Current A 63 70
BIL/ SIL (HV to LV)BIL/ SIL (HV to Ground)BIL/ SIL (LV to Ground)
kVkVkV
1300/11751425/1300450/350
150/150250/250150/150
Ratings of Capacitors C1 & C2 of 12/24 filterRatings of Capacitors C1 & C2 of 12/24 filter
Make KLK Electro Materials, Spain
Type KLK DT 12/24
Resistance at nominal current Ω 400
Tolerance % % +/-5
Total losses kW 160
Rated frequency Hz 50
BIL/ SIL (HV to LV)BIL/ SIL (HV to Ground)BIL/ SIL (LV to Ground)
kVkVkV
325/250325/25095/95
Ratings of Resistors of 12/24 & 12/36 filterRatings of Resistors of 12/24 & 12/36 filter
Make Trench Limited, Canada
Type Dry, Air core Dry, Air core
Nominal Inductance mH 14.71 8.19
Tolerance on Inductance % +/-1 +/-1
Continuous Current ratingDC CurrentMajor harmonicGeometric sum of Harmonic
CurrentTotal Current Stress
AmpsAmpsAmpsAmps
043 (12th )6060
0110 (12th )120120
BIL/ SIL (HV to LV)BIL/ SIL (HV to Ground)BIL/ SIL (LV to Ground)
kVkVkV
250/250450/250250/250
150/150250/250150/150
Minimum Creepage Distance mm 800 400
Ratings of Reactors of 12/24 filterRatings of Reactors of 12/24 filter
DC FilterDC Filter 12/36 TYPE12/36 TYPE
C1=1800 nF
R1=400 ΩL1=7.21 mH
L2=12.68mH
C1=3300 nF
Make ABB ABB
Nominal capacitance nF 1800 3300
Tolerance of Nominal Capacitance % +/- 0.5 +/-1.0
Maximum DC VoltageArithmetic sum of Harmonic VoltageTotal Voltage Stress
kVkVkV
53861624
-9.213
Geometric sum of Harmonic Current A 65 76
BIL/ SIL (HV to LV)BIL/ SIL (HV to Ground)BIL/ SIL (LV to Ground)
kVkVkV
1425/10501425/1050325/250
1425/10501425/1050325/250
Type of Fusing Internal Internal
Ratings of Capacitors C1 & C2 of 12/36 filterRatings of Capacitors C1 & C2 of 12/36 filter
Make Trench Limited, Canada
Type Dry, Air core Dry, Air core
Nominal Inductance mH 7.21 12.68
Tolerance on Inductance % +/-1 +/-1
Continuous Current ratingDC CurrentMajor harmonicGeometric sum of Harmonic
CurrentTotal Current Stress
AmpsAmpsAmpsAmps
044 (12th )6565
0116 (12th )123123
BIL/ SIL (HV to LV)BIL/ SIL (HV to Ground)BIL/ SIL (LV to Ground)
kVkVkV
250/250450/250250/250
150/150250/250150/150
Minimum Creepage Distance mm 1050 400
Ratings of Reactors of 12/36 filterRatings of Reactors of 12/36 filter
DC MEASURING DEVICESDC MEASURING DEVICES
Measurement on DC side for control, monitoring and Protection
AC CTs cannot be used on DC side – saturation DC current measuring devices – OPTODYNE
DC shunt – low value resistor mV drop from the shunt will be taken for determining the current To solve insulation problems – electrical signals are converted to
optical at the shunt and at control system converted to electrical Supply for the conversion process is obtained from the control panels in
the form of optical power DC voltage divider
Capacitive & resistor divider circuit Drop across the resistor scaled for determining the voltage Optical conversion process is same as the current measuring device
Details follows……Details follows……
66 UdL 4
Line 1
Pole1
4UdN
2 4 8
Electrode lines
2 4 8UdN 8
411Nos (4 HV+7 LV)
Pole204 Nos ( 2 HV+2 LV)
Line 2
6 UdL 46
Current Measuring Devices
Voltage Dividers
DC Current Measuring Device (OPTODYN) Lay out at HVDC Kolar
IdH
IdN
IdN Idee1
IdL
IdE
Idee2
Idee3
IdE
IdLIdH
Example for the Use of the Hybrid Optical Sensor
Iron C ore Induc tive C T S hun t R ogow sk i A ir C ore C T H V /E H V -L ine
C apac itiveV o ltage D iv ide r
R es is tanceV o ltage D iv ide r
Induc tive V o ltageTrans fo rm er G round Leve l
O PTO DYN TM
Functional ConceptFunctional Concept
Analog/ Digital
Digital/ Optical
Optical Energy
Electrical EnergyId
Shunt
Sensor Head at high voltage level
Optical Energy
Electrical Energy
Power fibre
Signal fibre
Optical
Digital
Power supply
Fibre optical cable
Digital control/ protection systemSIMADYN D
Control/ Protection system at ground level
Power Supply of Sensor Head
LO W P O W E RElectron ics at the
Sensor
O ptica l F iber
O ptica l In te rface , O ptica l P ower-M odu le (as part o f the O ptica l In te rface C ard)
Iso la tion of Synchronis ing s ignal frompower supply vo ltage level (carrier)
Power Supply O utputfor P recondition ing andT ransm itter E lectron ics
VoltageR egulator
Photocell-A rray(Power
C onverter)
5 VD C ca. 25 W forup to 9 channels from
SIM AD YN DSystem Power Supply
LA S E R D riverand Protection
LA S E RD iode Array
Optical Data Transfer
O ptica l In te rface
D igita l D ata for processing in C ontro l andProtection System s
O PT IC AL-R EC EIVER
BU FFER
BU R D EN -R ESIST O R(at C T only)
FastT ransients+
R FI-Prot.BU FFER
AN T I-ALIASIN G
FILT ER
12 B itA /D -
C onverter
O PT IC AL-T R AN S-M IT T ER
O ptica l F iber
Components1
23
4
5
6 7
8
9
10
11
2 Voltage to Light Telegram Conversion
3 Fibre Optic Transmission to Ground Level
4 Composite Insulator
5 Control or Protection System
6 Light Pulses for Power Supply
7 Power Supply for Sensor Head
8 Rogowski Coil for Harmonic Current Measuring
9 Control of Active DC Filter
1 Ohmic Shunt at High DC Voltage Level for Direct Current Measuring
10 Hybrid Direct Current Measuring System with Fibre Optic Transmission
11 Sensor Head
Current measuring device – componentsCurrent measuring device – components
Redundancy Concept
Id
Shunt
Sensor Head Pole control System 1
Sensor Head
Sensor Head
Sensor Head
Protection System 1
Protection System 2
Pole control System 2
common composite insulator and fibre optic cable ground level; control buildinghigh voltage level; switchyard
complete redundancy from sensor head via FO cable to control/ protection equipment only one Analog/ Digital conversion per signal path direct digital signal processing
DC Measuring Scheme: Conventional DC Transducer
0
Signal
Am plifier
D igita l C ontro l System
D igita l S igna l
P rocessor
0
Isolation
Am plifier
Conventional DC Transducer: Accuracy < +-0,5%typical +- 0,2% typical +- 0,1%
Conventional DC Measuring Schem e: Total Accuracy < +-0,8%
to redundant control system or
protection system
0
Isolation
Am plifier
DC Measuring Scheme: Hybrid-Optical DC Measuring System
O P T O D YN
E lectron ic S ensor H ead
0
Current Sensor:
typical +- 0,2% typical +- 0,5%
Hybrid-Optical DC Measuring System : Total Accuracy < +-0,75%
D igita l C ontro l S ystem
D igita l S igna l
P rocessor
0,0%
Comparision to Comparision to Conventional SolutionConventional Solution
Comparison between Hybrid-Optical Conventional DC Measuring System The weight of the new measuring device is
reduced from 4,000 kg to 100 kgNo additional Post InsulatorsNo electromagnetic interference (EMI) due to fibre optic linksFull redundancy up to the measuring locationExcellent dynamic performance
Picture 2
Hybrid-Optical Measuring Device Measuring Shunt
Sensor Head Box
Composite Insulator
incl. Fiber Optics
Connection Box
Sensor Head Box with Sensors
Assembly of Shunt
OPTODYN Sensor
Analoge Input Signal from Shunt
Optical Data Link
Optical Power Supply Link
Summary
Measures DC current quantities up to the range of 18,000 A
High voltage insulation level up to 500 kV rated DC voltage
Current measuring by a high precision shunt
Light construction
High insulation capability also under extreme environmental conditions
Less pollution due to less electrostatic potential of silicon surface
Hydrophobic silicon material reduces risk of leakage currents
No electromagnetic interference by use of fibre optic cables
Summary
Optical powered electronics at high voltage level
Optical signal transmission
Optical receivers directly placed in the control or protection system
Separate channels for control and protection including their redundant
subsystems
Excellent dynamic Performance
Bandwidth 0 - 7 kHz (depending on application)
Overall system accuracy 0.75 %
Signal delay 160 µs
Temperature operating range -40 C to +50 C
DC Voltage Measurement
DC Voltage Measurement
System DescriptionSystem Description
The Valve Cooling System is a single closed loop The Valve Cooling System is a single closed loop deionised water system. Heat transfer to the ambient is deionised water system. Heat transfer to the ambient is provided by dry coolers. The Valve Cooling System is for one provided by dry coolers. The Valve Cooling System is for one pole and works independent of other cooling and air pole and works independent of other cooling and air conditioning systems.conditioning systems.
Spray water will be used if the water temperature rises Spray water will be used if the water temperature rises above controller set point value.above controller set point value.
Design Basis
Kolar Station Talcher Station
Maximum Dry Bulb One Hour Average 450C 500C
Minimum Dry Bulb One Hour Average 20C 00C
Total Cooling Capacity 4340kW 4053kW
Water flow 4140 ltr./min 4350 ltr./min
Water Inlet Temperature MAX 500C 500C
Water Outlet Temperature Average 620C 620C
Water Conductivity <0.5μS/cm <0.5μS/cm
Redundant Circulating Pumps One of two One of two
Spray Water Storage for 24hrs 24hrs
Flow Diagram
Two centrifugal circulating pumps
One pump - operating Other pump - standby
Periodical automatic pump changeover.
Changeover to the stand by pump takes place in case of failure of the operating pump
Capacity of Motor – 45KW Pump – 265Cu.m/Hr
VALVE COOLING MAIN PUMPVALVE COOLING MAIN PUMP
In the main water line to the thyristor valves locates a 50 micron filter
The filter is used for start up and cleaning and later on for safety, that no particle greater than 50 micron can enter the thyristor valves
VALVE COOLING - MAIN FILTER VALVE COOLING - MAIN FILTER
Main filter consists of group of filter cartridges as shown in the figure
If the filter gets chocked for any reason, differential pressure will be sensed and this warns for maintenance
VALVE COOLING - MAIN FILTER VALVE COOLING - MAIN FILTER
A storage tank with a pressure pump is placed on the pump skid for the first filling with deionised water and for compensation of evaporated water during operation
The make up water system works automatically and keep the expansion tank water level constant
The make up water flows from the storage tank through a 50 μm filter, then the make up water pass the ion exchanger and flows finally into the main water circuit
VALVE COOLING – MAKE UP WATER TANKVALVE COOLING – MAKE UP WATER TANK
Two ion exchanger chambers are installed on the pump skid
The ion exchanger is hydraulically switched in bypass to the main water line
A mixture of 50% anion and 50% cation (H+/OH-) is used for the resin
Water flows from top to the bottom through the ion exchanger
VALVE COOLING – ION EXCHANGERSVALVE COOLING – ION EXCHANGERS
Six cooling towers are installed to cool down the fine hot water coming out from the valves
One tower consist of two cooling coils with stainless steel tubes and seawater resistance aluminium fins.
Two axial type fans are mounted on the top flow. The fans work on the suction side in parallel to the cooling coil surface without baffle sheets.
Because there is no baffle sheet, the working fan will cover the whole cooling coil surface, therefore the lost cooling capacity will be less then 50% of the tower.
VALVE COOLING SYSTEM – COOLING TOWERSVALVE COOLING SYSTEM – COOLING TOWERS
Each fan is provided with Variable frequency Drive (VFD). This regulates the speed of the fan depending on the water temperatureIf one fan fails, the speed of the remaining fans will be increased automatically.
•A spray water distribution pipe with nozzles locates on the top of each cooling coil
•Water will be sprayed over the coil if the water inlet temperature exceeds specified limit
To avoid scaling on the cooling coil fins, the spraying water will be treated by a reverse osmosis* unit.
The incoming water from the station supply will be filtered, softened by the reverse osmosis unit and stored in the spray water storage tank.
The same water is used to make up the loss in the main water circuit
High pressure pumps each of 100% capacity are used for the spray water lines.
*slow change in concentration: the flow of a solvent by diffusion through a semi permeable membrane from a more concentrated solution to a less concentrated one, until the concentrations are equalized. It is a major factor in regulating the movement of water into and out of tissues in living organisms.
Water Treatment plantWater Treatment plant
Controlled by two redundant SIMATIC S95U programmable controller.
The PLC working independent of each other.
The PLC generates the necessary status, alarm and trip signals for the station control.
The inlet water temperature to the Thyristor valve modules is maintained at constant value for every load and ambient conditions.
A digital process controller SIPART DR22 is used for the temperature control
The controller output signal is used for the set point of the cooling fan speed.
Start and stop signal for the fans is given by the PLC.
80 KVA UPS is provided as backup power supply. Since the outage of main pump generates immediate trip to the pole.
VALVE COOLING SYSTEM-CONTROL VALVE COOLING SYSTEM-CONTROL
Expansion Tank The expansion tank is place on the highest point of the cooling system.
The tank size is big enough to store the expanded fine water volume. The expansion tank is an open type expansion tank, the construction of
the tank allows the air to come in contact with the water, but dust can not enter the tank.
Thyristor valve manufacturer requires a oxygen saturated water, therefore the need of an open system.
The tank is connected to the suction side of the main water line, the connection to the discharge main water line will be used for circulation and for venting.
Valve Hall Ventilation system Flow DiagramValve Hall Ventilation system Flow Diagram
AIR INLET 5m ABOVE GROUND LEVEL
Valve Hall Ventilation system Valve Hall Ventilation system
Consists of the primary circuit (Air Ventilation Circuit) and Control System Open loop system – supply air will taken in and left out through the exhaust
dampers One ventilation system is in operation while the other one is in stand by mode. The outdoor air will be entering the unit by a concrete block duct in a level of
5 m to avoid the dust concentration at the floor level. The supply air will filtered in two stages – pre filter and fine filter The supply air will be distributed into the valve hall by high speed air nozzles. The exhaust air flows via dampers and weather guard louvers into the
atmosphere. A bypass damper and a heater enables the circulation of air from the valve
hall back to the unit in case of no load or during start up. Through out the process, positive pressure will be maintained in the valve hall
to prevent dust to enter the valve hall. Positive pressure is maintained with the automatic control of exhaust dampers
One single ventilation unit consist of One axial type fan speed regulated One electrical heater One air filter bag type as a pre filter One air filter bag type as a high efficiency filter One Supply air damper with DC drive One Return air damper with DC drive One Bypass or re-circulating damper with DC drive
The two exhaust dampers with DC drives combined with a weather guard louver, as well as the air inlet weather guard louver working together with the two ventilation units. In case of failure of the operating unit, a switchover to the stand by unit takes place.
A periodically automatic switchover is also provided by a programmable timer. The timer can operate in automatic or manual mode.
Valve Hall Ventilation system-componentsValve Hall Ventilation system-components
The ventilation system will be controlled by two SIMATIC S95U programmable controller.
The PLC‘s are working independent from each other; a switch off of one PLC for repair, replacement or service will not disturb the ventilation system operation.
The input signals from the single sensor will be wired parallel on the two PLC.
The output signal from the PLC working on the same relay coupled by a diode.
The PLC generates also the necessary status, alarm and trip signals for the station control.
Ventilation system - ControlVentilation system - Control
KOLAR SINGLE LINE DIAGRAMKOLAR SINGLE LINE DIAGRAM
AC PLC (Noise) FilterAC PLC (Noise) Filter
Equipment Designation Kolar=20C08.C C1/TD, C2/TD=20C10.C C1/TD, C2/TD
Talcher=10C03.C C1/TD, C2/TD=10C05.C C1/TD, C2/TD
Number of single phase units 6 6
Rated Capacitance 40 nF 80 nF
Nominal voltage 400 kV 400 kV
Short -time current (1s) 40 kA 40 kA
Basic Insulation level (BIL) 1425 kV 1425 kV
Switching Insulation level (SIL) 1050 kV 1050 kV
Min creepage distance 10500 mm 10500 mm
AC PLC FILTERAC PLC FILTER
VALVE TIMING PTVALVE TIMING PT
•Inductive Voltage Transformer - Connected to converter Inductive Voltage Transformer - Connected to converter transformer 400 KV sidetransformer 400 KV side
•Pole control gets the zero crossings of the Voltage on line side Pole control gets the zero crossings of the Voltage on line side and uses this as the reference for generating firing signals for and uses this as the reference for generating firing signals for the valvesthe valves
•This PT is used only for firing signal generation – not used for This PT is used only for firing signal generation – not used for nay protection tasknay protection task
•It is inductive voltage It is inductive voltage transformer transformer
•Oil filled – Oil type Shell Oil filled – Oil type Shell Diala DDiala D
•Make – Trench.Make – Trench.
•Primary/secondary Primary/secondary voltage ratio – 400√3/110 voltage ratio – 400√3/110 √ √ 33
VALVE TIMING PTVALVE TIMING PT
VESDA SYSTEMVESDA SYSTEM
Air sampling based detection system for early detection of incipient smoke / fire in Valve Hall.
Installed in each Valve Hall. Sufficient points are well distributed over each multiple valve
structure & inside the ventilation air duct for faster response of hazard.
The VESDA detectors are located such that there is no condensation due to temperature differences between the sampled air & the outside temperature.
Air is sampled by PVC (red) pipes - no risk of flashover or corona inside the valve hall.
The detection system has VESDA laser scanner & laser compact. This gets the signal from the sampling pipes which are of PVC make & are supported at regular interval of 1.5 m. For more sensitivity & easy detection,the sampling area is divided into 4 zones.The detector has 4 alarms namely .
Alert Action / Prealarm Fire 1 Fire 2
VESDA – VERY EARLY SMOKE DETECTION & ANALYSER VESDA – VERY EARLY SMOKE DETECTION & ANALYSER SYSTEMSYSTEM
VLC – VESDA LASER COMPACTVLC – VESDA LASER COMPACT
VLS – VESDA LASER SCANNERVLS – VESDA LASER SCANNER
PVC conduit
VESDA laser compact
VALVE - HALL
Vent diameter – 4 mm
End cap – 4 mm
VESDA - LAYOUTVESDA - LAYOUT
VLC
VESDA - LAYOUT
AIR SAMPLING PVC
Each detector has separate settings of alarm Level
DETECTOR ALERT ACTION FIRE 1 FIRE 2
SCANNER 0.075 % 0.13 % 0.19 % 0.25 %
COMPACT[ SUPPLY AIR ]
0.15 % 0.3 % ----- 0.5 %
COMPACT[ RETURN AIR ]
0.075 % 0.16 % ----- 0.25 %
NOTE : All values have the unit obscuration / m or Ob / m
In the event of detection of smoke in valve hall
Ventilation system shall be tripped automatically.
The exhaust dampers shall be opened. The valve-hall shall be de-energized. The smoke management system shall indicate
“smoke evacuation mode”. The audible fire alarm system in the station
shall also be activated.
Voltage – 18 to 30 V DC. Power – 5.8 to 9.6 W. Current – 240 to 400 mA. Sensitivity – 0.005 to 20 % Ob/m Operating temperature
Detector ambient : 0 to 39oC Sampled air : 20 to 60oC Humidity : 10-95%RH.
Maximum area of coverage – 2000 m2. Up to 18000 events can be stored on a FIFO basis. Four levels of fault warning – Alert,Action,Fire1,Fire2. Relays – 12 relays rated at 2A @ 30 V DC.
VESDA LASER SCANNER - SPECIFICATIONSVESDA LASER SCANNER - SPECIFICATIONS
Voltage – 18 to 30 V DC Power – 4 W Current – 170 mA Sensitivity – 0.005 to 20 % Ob/m Operating temperature
Detector ambient : 0 to 39oC Sampled air : 20 to 60oC
Maximum area of coverage – 500 m2
Up to 12000 events can be stored on a FIFO basis Smoke level, alarms & faults with time & date stamp Relays – 3 relays 2A @ 30 V DC
VESDA LASER SCANNER - SPECIFICATIONSVESDA LASER SCANNER - SPECIFICATIONS
Converter requires reference ground for insulation coordination, control & protection
DC currents cause corrosion in metallic structures, hence generally the grounding is done at a safe distance away from HVDC stations (30 to 35 Km)
Reliability of HVDC System When one line is faulty then by using earth as return path 50% of rated Bipole
power can be transmitted. When one pole trips other pole continues in ground return with over load
capacity of that pole thus providing transient stabilty / sudden loss of power Eliminates the requirement of a separate line as return path
During balance bipolar operation no current flows through the ground however it provides a return path
Located at Sidalagatta about 32 km from Kolar Station. Similar station exits at Talcher.
ELECTRODE STATIONELECTRODE STATION
Electrode station - LayoutElectrode station - Layout
EARTH ELECTRODE EARTH ELECTRODE
Conductor type ACSR “Bersimis” Double bundle - 2 x 725.2 Sq.mm Length – 32 Kms DC resistance at 20°C – (0.0421 / 2 ) ohms / km Electrode resistance < 0.3 ohms Electrode – Double ring of diameter 450/320m Each ring consist of a buried coke bed at approx. 2.5 m depth. The outer ring is divided into six sections and the inner ring into two
sections Current is distributed by an overhead system to the feeding cables of
each electrode section. The cables are connected to the buried electrode.
The electrodes are equipped with detecting wells for monitoring the temperature and humidity development of the soil
TALCHERTALCHERKOLARKOLAR REPEATERREPEATER
PLCC PANELS
PLCC PANELS
PLCC PANELS
PLCC PANELSPLCC
PANELS
PLCC PANELS
BTBT
BTBT
BT= BALANCING TRANSFORMER
PLCC SCHEMATICPLCC SCHEMATIC
Pole 1 DC Line Pole 1 DC Line
Pole 2 DC Line Pole 2 DC Line
REPEATER STATIONREPEATER STATION
•Repeater station is required due to the long distance of the line - 1400Km (approx.)
•Located at Jungareddygudem (Rajahmundry) almost at a distance of 630 km from Kolar
•Conventional AC stations don’t require repeater station in between the line
•Modulated signals consisting of Data, protection and speech are sent to repeater station from one end over the DC lines
•Signals are demodulated, amplified and again modulated and sent to the other end from repeater station – thus working as a signal amplifier
•ABB PLCC panels ETL 580 model are used which works on advanced DSP technology
REPEATER STATION-REPEATER STATION-Other EquipmentOther Equipment
•PLCC signals are injected to the line through the PLC coupling capacitors
•For maintenance works on the PLC equipment, earth switches are provided
•PLCC panels requires 48V DC supply - provided from batteries
•Auxiliary supply is be provided from local SEB supply
•DG set is provided as backup to the SEB supply