M/s. GREENESOL POWER SYSTEMS PVT.LTD., BANGALORE
Date: 1/3/2011 Time: 11:28 AM
CT & PT SIZING CALCULATION
OWNER
M/s. SIMHAPURI ENERGRY PVT LTD
OWNER ENGINEER EPC CONTRACTOR ORGINATOR EPC Project SYSTEM DETAILS
M/s. DEVELOPMENT CONSULTNATS PVT LTD
Generator Rating Generator Voltage
Ref.No.
2001/CTPT/01
Revision
07
Date
03.01.11
M/s. MADHUCON PROJECTS LTD M/s. M.N. DASTUR & COMPANY (P) LTD 2 X 150 MW THERMAL POWER PLANT (PHASE -II)
150 :15.75KV
Generator PF Generator FLC
:
0.8 KW
150000
Ö3VCosF Generator FLC After 15% of Over ucrrent
6873.419114 7904.431981
=
(1.732*15.75*0.8)
150000
6873.419114
21.8232
Amps Amps
Hence the Selected CT ratio will be 800 0/5 Amps. References : 1. AE Meter Catalogue 2. GE Manual 3. Auto synchroniser - Woodward manual 4. Single Line Diagram No. 2001010 101, Revision-05 1. Generator Control Panel (GCP)
Description
Sl. No. 1 2 3 4 5 6
Digital Ammeter Digital Voltmeter Digital Frequency Meter Digital MW Meter Digital MVA Meter Digital MVAR Meter
8 9 10 11 12 13 14 15 16 17
Double Voltmeter Double Frequency Meter MW Transducer Multi Transducer Synchroscope Autosynchroniser Check Synchronising Relay No Volt Relays PT Fuse failure relay Cable Burden
CT Circuit (CT4 ) Neutral side Metering core. Burden in VA Qty Total Burden in VA 1 1/phase 1 1 1 1 1 1 1 1 1 1 1 1 0.2955
2 3 2
Total Burden
2 3 0.591 10.591
PT Circuit (PT3: Core-1) Metering core Burden in VA Qty Total Burden in VA 2 1 2 1 1 1 3 1 3 3 1 3 3 1 3 2 2 1 1 6 1 2.5 3 6.5 0.435
1 1 2 3 1 1 1 2 1 2
2 2 2 3 6 1 2.5 6 6.5 0.87 44.87
2. AVR Panel
Sl. Description No. 1 2 3 4 5 6 7
Voltmeter Ammeter PF Meter AVR Droop Ckt. AVR Cards PT Fuse failure relay Cable Burden
CT Circuit (CT:5 & 6) Ph Phase side Metering Core Burden in VA Qty Total Burden in VA 1 1 1 1 1 1 5 2 10 0.2955 2 0.591
Total Burden
12.591
PT Circuit (PT1&2: Core-1) Burden in VA Qty Total Burden in VA 2 1 2 1 1 1 10 2 20 20 6.5 1 6.5 0.435 2 0.87 30.37
3. Generator Relay Panel (GRP)
Sl. Description No. 1 Multifunctional Relay-1 (G60) 2 PT Fuse failure 3 Cable Burden
CT:(3.1-3.3 ) CT7:( 7.1-7.3 ) Protection Core Burden in VA Qty Total Burden in VA 3 1 3 0.2955 2 0.591 Page 1 of 7
PT Circuit (PT3 : Core-2) Protection Core Burden in VA Qty Total Burden in VA 3 1 3 6.5 1 6.5 0.435 2 0.87
M/s. GREENESOL POWER SYSTEMS PVT.LTD., BANGALORE
CT & PT SIZING CALCULATION
OWNER
M/s. SIMHAPURI ENERGRY PVT LTD
OWNER ENGINEER EPC CONTRACTOR ORGINATOR EPC Total Burden
M/s. DEVELOPMENT CONSULTNATS PVT LTD
Date: 1/3/2011 Time: 11:28 AM
Ref.No.
2001/CTPT/01
Revision
07
Date
03.01.11
M/s. MADHUCON PROJECTS LTD M/s. M.N. DASTUR & COMPANY (P) LTD
Sl. Description No. 1 Multifunctional Relay-2 (G60) 2 PT Fuse failure 3 Cable Burden
3.591
CT :(2.1-2.3 ) CT8:( 8.1-8.3 ) Protection Core Burden in VA Qty Total Burden in VA 3 1 3 0.2955 2 0.591
Total Burden
3.591
10.37
PT Circuit (PT3 : Core-2) Protection Core Burden in VA Qty Total Burden in VA 3 1 3 6.5 1 6.5 0.435 2 0.87 10.37
4. GT-Transformer Relay Panel (TRP)
Sl. Description No. 1 Multifunctional Relay-2 (T60) 2 Cable Burden
CT:(19.1-19.3 ) Protection Core Burden in VA Qty Total Burden in VA 3 1 3 0.2955 2 0.591
Total Burden
Sl. Description No. 1 Multifunctional Relay-1 (T60) 2 Cable Burden
3.591
CT :(20.1-20.3 ) Protection Core Burden in VA Qty Total Burden in VA 3 1 3 0.2955 2 0.591
Total Burden
3.591
PT Circuit (PT : From GCB) Protection Core Burden in VA Qty Total Burden in VA 3 1 3 0.435 2 0.87 3.87
PT Circuit (PT : From GCB) Protection Core Burden in VA Qty Total Burden in VA 3 1 3 0.435 2 0.87 3.87
5. TVM (MAIN & CHECK)
Sl. Description No. 1 Trivector Meter (Main & Check) a e ur en
Burden in VA 1 .
CT Circuit (CT) - TVM Qty Total Burden in VA 1 1 .
Total Burden
1.591
Total Burden on Netural side CT4: (GCP METERING - Metering core)
10.591 VA
Total Burden on Netural side CT3: (GE-G60-1 - Protection core)
:PS Core Vk>=500V Imag<30mA@Vk/2
Total Burden on Netural side CT2: (GE-G60-2 - Protection core)
:PS Core Vk>=500V Imag<30mA@Vk/2
Total Burden on Netural side CT1: (Over a ll Differentaila - Protection core)
:PS Core Vk>=500V Imag<30mA@Vk/2
Total Burden on Phase side CT5: (AVR Metering - Metering core)
12.591 VA
Total Burden on Phase side CT6: (AVR Sensing - Metering core)
12.591 VA
Total Burden on Phase side CT7: (GE-G60-1 - Protection core)
:PS Core Vk>=500V Imag<30mA@Vk/2
Total Burden on Phase side CT8: (GE-G60-2 - Protection core)
:PS Core Vk>=500V Imag<30mA@Vk/2
Total Burden on Phase side CT19: (GE-T60-2 - Protection core)
:PS Core Vk>=500V Imag<30mA@Vk/2
Total Burden on Phase side CT20: (GE-T60-1 - Protection core)
:PS Core Vk>=500V Imag<30mA@Vk/2
Hence, the selected CT & PT's are as below
Page 2 of 7
PT Circuit (PT) - Metering core Burden in VA Qty Total Burden in VA 3 1 3 . . 3.87
M/s. GREENESOL POWER SYSTEMS PVT.LTD., BANGALORE
CT & PT SIZING CALCULATION
OWNER
M/s. SIMHAPURI ENERGRY PVT LTD
OWNER ENGINEER EPC CONTRACTOR ORGINATOR EPC Neutral Side CT's.
M/s. DEVELOPMENT CONSULTNATS PVT LTD M/s. MADHUCON PROJECTS LTD M/s. M.N. DASTUR & COMPANY (P) LTD
CT Ratio : Metering core :
8000/5A (CT-4-Neutral side) GCP CL : 0.2S,30 VA
CT Ratio : Protection core :
8000/5A (CT-2-Neutral side) GE-60-2 CL : PS, Vk>=500V,Imag<30mA@vK/2
CT Ratio : Protection core
8000/5A (CT-1-Neutral side) 87O Over All Differentail CL : PS, Vk>=500V,Imag<30mA@vK/2
CT Ratio : Protection core
8000/5A (CT-3-Neutral side) GE-60-1 CL : PS, Vk>=500V,Imag<30mA@vK/2
Phase Side CT's.
CT Ratio : Metering core
8000/5A (CT-5-Phase side) AVR CL : 0.2,30 VA
CT Ratio : Metering core :
8000/5A (CT-6-Phase side) AVR Sensing CL : 0.2,30 VA
CT Ratio : Protection core
8000/5A (CT-7-Phase side) GE-60-1 CL : PS, Vk>=500V,Imag<30mA@vK/2
CT Ratio : Protection core
8000/5A (CT-8-Phase side) GE-60-2 CL : PS, Vk>=500V,Imag<30mA@vK/2
CT Ratio : Protection core
8000/5A (CT-19-Phase side) GE-T60-2 CL : PS, Vk>=500V,Imag<30mA@vK/2
CT Ratio : Protection core
8000/5A (CT-20-Phase side) GE-T60-1 CL : PS, Vk>=500V,Imag<30mA@vK/2
PT's
PT Ratio : Metering core : Protection core :
15.75kV/Ö3 / 110V/Ö3 / 110V/Ö3 Core1 : CL : 0.2, 50VA To AVR Sensing Core2 : CL : 3P, 100VA Spare Core
PT-1
PT Ratio : Metering core : Protection core :
15.75kV/Ö3 / 110V/Ö3 / 110V/Ö3 Core1 : CL : 0.2, 50 VA To AVR Metering Core2 : CL : 3P, 100VA To GE-60-1
PT-2
PT Ratio : Metering core : Protection core :
15.75kV/Ö3 / 110V/Ö3 / 110V/Ö3 Core1 : CL : 0.2, 50 VA To GCPMetering Core2 : CL : 3P, 100VA To GE-60-2
PT-3
Cable Burden Cable lead resistance per km (2.5Sq mm) Cable length between relay to Field Cable burden
8.7 ohm/ km 50 meters Considered 2 I *R 0.435 VA
Cable lead resistance per km (4.0 Sq MM) 5.91 ohm/ km Cable length between relay to Field 50 meters Considered I *R Cable burden 0.02955 VA
Page 3 of 7
Date: 1/3/2011 Time: 11:28 AM
Ref.No.
2001/CTPT/01
Revision
07
Date
03.01.11
M/s. GREENESOL POWER SYSTEMS PVT.LTD., BANGALORE
CT KNEE POINT VOLTAGE CALCULATIONS FOR 8000A OWNER
M/s. SIMHAPURI ENERGRY PVT LTD
OWNER ENGINEER EPC CONTRACTOR ORGINATOR EPC ENGINEER Project
M/s. DEVELOPMENT CONSULTNATS PVT LTD
Date: 1/3/2011 Time: 11:28 AM
Ref.No.
2001/CTPT/02
Revision
07
Date
03.01.11
M/s. MADHUCON PROJECTS LTD M/s. M.N. DASTUR & COMPANY (P) LTD 2 X 150 MW THERMAL POWER PLANT (PHASE -II)
SYSTEM DETAILS Generator Rating Generator Voltage
: :
150 MW 15.75 KV
Generator PF
:
0.8 Amps
Generator FLC
:
6873 Amps
Sub transient reactance CT winding resistance Primary CT current
Xd"
:
Rct
:
5 Ohms
:
8000 Amps
:
5 Amps
Secondary CT current
13.9 %
Resistance of conn. Leads or Cable resistance
RL
:
0.591 ohms
Internal resistance of Relay
Rp
:
0.05 ohms
Vkp
=
CT Knee point voltage
If
considered 100 meter 5.91 Ohms / KM
2.If(sec).(Rct+RL+Rp) MW/(root3xkVxPFxXd")
=
150MW/(root3x15.75kVx0.8x0.139)
If(sec) = = Vkp
considered
= =
CT Knee point voltage
0.139 p.u.
= =
49.45 KA If(p ri)/CT ratio 30.91 Amps 2x30.906x (5+0.591+0.05) 348.7 Volts
Page 4 of 7
at 90 Deg.C
M/s. GREENESOL POWER SYSTEMS PVT.LTD., BANGALORE
Date: 1/3/2011 Time: 11:28 AM
CT & PT SIZING CALCULATION FOR 1500A OWNER
M/s. SIMHAPURI ENERGRY PVT LTD
OWNER ENGINEER EPC CONTRACTOR ORGINATOR EPC ENGINEER
M/s. DEVELOPMENT CONSULTNATS PVT LTD
Project
2 X 150 MW THERMAL POWER PLANT (PHASE -II)
Ref.No.
2001/CTPT/03
Revision
07
Date
03.01.11
M/s. MADHUCON PROJECTS LTD M/s. M.N. DASTUR & COMPANY (P) LTD
SYSTEM DETAILS
UAT Rating UAT Primary Voltage
31.5 MVA 15.75 KV
UAT primary rated : KVA current Ö3V
Generator FLC After 15% of Over ucrrent
1154.734411 1327.944573
31500 (1.732*15.75)
=
31500 27.279
1154.734411
Amps Amps
Hence the Selected CT ratio 1500/1 Amps is suitable for the application. References : 1. AE Meter Catalogue 2. GE Manual 3. Single Line Diagram No. 2001010 101, Revision-04 1. UAT Protection & Relay Panel
Sl. No. 1 2 3 4
Description Digital Ammeter MW Transducer Digital MW Meter Cable Burden
CT Circuit (CT 11.1-11.3 &16.1-16.32 ) Burden in VA Qty Total Burden in VA 1 1/phase 1 1 1 1 1 3 3 0.2955 2 0.591
Total Burden
5.591
PT From GCB - Protection Core Burden in VA Qty Total Burden in VA 1 1 1 1 1 1 0.435 2 0.87 2.87
2. Relay Panel (GRP)
Sl. Description No. 1 Multifunctional Relay-1 (T60) 2 Cable Burden
CT:(9.1-9.3 & 14.1-14.3 ) Protection Core Burden in VA Qty Total Burden in VA 3 1 3 0.2955 2 0.591
Total Burden
Sl. Description No. 1 Multifunctional Relay-2 (T60) 2 Cable Burden
3.591
CT:(10.1-10.3 & 15.1-15.3 ) Protection Core Burden in VA Qty Total Burden in VA 3 1 3 0.2955 2 0.591
Total Burden
3.591
PT From GCB - Protection Core Burden in VA Qty Total Burden in VA 3 1 3 0.435 2 0.87 3.87
PT From GCB - Protection Core Burden in VA Qty Total Burden in VA 3 1 3 0.435 2 0.87 3.87
3. TVM
Sl. Description No. 1 Trivector Meter (Main & Check) 2 Cable Burden
CT:(12.1-12.3 & 17.1-17.3 ) Metering Core Burden in VA Qty Total Burden in VA 1 1 1 0.2955 2 0.591
Total Burden
1.591
Total Burden on UAT Primary side CT9&CT14 : (GE-T60-1 - Protection core)
:PS Core Vk>=500V Imag<30mA@Vk/2
Total Burden on UAT Primary side CT10&CT15: (GE-T60-2 - Protection core)
:PS Core Vk>=500V Imag<30mA@Vk/2
Total Burden on UAT Primary side CT11&CT16: (UAT METERING - Metering cor 5.87 VA Total Burden on UAT Primary side CT12&CT17: (Metering core for TVM)
Page 5 of 7
1VA
PT From GCB - Protection Core Burden in VA Qty Total Burden in VA 3 1 3 0.435 2 0.87 3.87
M/s. GREENESOL POWER SYSTEMS PVT.LTD., BANGALORE
CT & PT SIZING CALCULATION FOR 1500A OWNER
M/s. SIMHAPURI ENERGRY PVT LTD
OWNER ENGINEER EPC CONTRACTOR ORGINATOR EPC ENGINEER
M/s. DEVELOPMENT CONSULTNATS PVT LTD M/s. MADHUCON PROJECTS LTD M/s. M.N. DASTUR & COMPANY (P) LTD
Total Burden on UAT Primary side CT13&CT18: (Over all DifferentailProtection)
:PS Core Vk>=500V Imag<30mA@Vk/2
Hence, the selected CT & PT's are as below CT Ratio : Protection core :
1500/1A (CT-9-UAT Primary side) UAT-TRP-T60-1 CL : PS, Vk>=500V,Imag<30mA@vK/2
CT Ratio : Protection core :
1500/1A (CT-10-UAT Primary side) UAT-TRP-T60-2 CL : PS, Vk>=500V,Imag<30mA@vK/2
CT Ratio : Metering core :
1500/1A (CT-11-UAT Primary side) UAT-Metering CL : 0.2S,30 VA
CT Ratio : Metering core :
1500/1A (CT-12-UAT Primary side) U AT-Metering (TVM) CL : 0.2S,30 VA
CT Ratio : Protection core :
1500/1A (CT-13- 87O Over All Differentail-UAT Primary side) CL : PS, Vk>=500V,Imag<30mA@vK/2
PT's
PT Ratio : Metering core : Metering core :
15.75kV/Ö3 / 110V/Ö3 / 110V/Ö3 Core1 : CL : 0.2, 30VA To UAT Metering Core2 : CL : 0.2, 30VA To Synch
PT From GCB
Cable Burden Cable lead resistance per km (2.5Sq mm) Cable length between relay to Field Cable burden
8.7 ohm/ km 50 meters Considered I *R 0.435 VA
Cable lead resistance per km (4.0 Sq MM) Cable length between relay to Field Cable burden
5.91 ohm/ km 50 meters Considered I *R 0.02955 VA
Page 6 of 7
Date: 1/3/2011 Time: 11:28 AM
Ref.No.
2001/CTPT/03
Revision
07
Date
03.01.11
M/s. GREENESOL POWER SYSTEMS PVT.LTD., BANGALORE
CT KNEE POINT VOLTAGE CALCULATIONS FOR 1500A OWNER
M/s. SIMHAPURI ENERGRY PVT LTD
OWNER ENGINEER EPC CONTRACTOR ORGINATOR EPC ENGINEER Project
M/s. DEVELOPMENT CONSULTNATS PVT LTD
Date: 1/3/2011 Time: 11:28 AM
Ref.No.
2001/CTPT/04
Revision
07
Date
03.01.11
M/s. MADHUCON PROJECTS LTD M/s. M.N. DASTUR & COMPANY (P) LTD 2 X 150 MW THERMAL POWER PLANT (PHASE -II)
SYSTEM DETAILS Transformer Rating Transformer HV Voltage
: :
31.5 MVA 15.75 KV
Primary Rated Current
:
1154 Amps
Sub transient reactance CT winding resistance
Xd"
:
Rct
:
5 Ohms
:
1500 Amps
:
1 Amps
Primary CT current Secondary CT current
12.5 %
Resistance of conn. Leads or Cable resistance
RL
:
0.591 ohms
Internal resistance of Relay
Rp
:
0.05 ohms
Vkp
=
CT Knee point voltage
If
considered 100 meter 5.91 Ohms / KM
2.If(sec).(Rct+RL+Rp) MVA/(root3xkVxXd")
=
31.5MVA/(root3x15.75kVx0.125)
If(sec) = = Vkp
considered
= =
CT Knee point voltage
0.125 p.u.
= =
9.238 KA If(p ri)/CT ratio 6.159 Amps 2x30.906x (5+0.591+0.05) 69.48 Volts
Page 7 of 7
at 90 Deg.C
