Distance Relay Model - uidaho.edu · Distance Relay Model The MathCAD sheet below implements some...
Transcript of Distance Relay Model - uidaho.edu · Distance Relay Model The MathCAD sheet below implements some...
ECE 526: Protection of Power Systems
Lab 1; Page 1/22Spring 2017
Distance Relay Model
The MathCAD sheet below implements some basic relay calculations. The file takes data read from a Comtrade file and postprocesses it.
The matrix "data" below is the data captured from a COMTRADE "*.dat" file. To read in a data file remove the table currentlyat the top of the file. Then choose "Insert" ---> "Component".
This will open a dialog box. One option is to choose "Input Table". * Then select the first cell in the table and right click your mouse and choose "Import". * Then browse to the "*.dat" COMTRADE file and select. This will fill in the data in the table. Then name the variable as "data"
Another option is to choose "File Read or Write".* This will open a dialog box, choose Text file* Browse for file with extension .txt or .csv. * Your assignments will tell you which files to open.
The example below uses the File Read or Write option.
Read Comtrade File Data
1. Read Comtrade Configuration File:
config
...\FSLG75.cfg
Right click on the floppy disk icon and select "Choose File" toopen a file browser. Choose the *.cfg file from the contrade file(you will need to type the extension). If you are using MathCAD13 or higher, right click and select "Properties"
data
...\FSLG75.dat Right click on the floppy disk icon and select "Choose File" to
open a file browser. Choose the *.dat file from the contrade file (itshould be an accepted file type)
ECE 526: Protection of Power Systems
Lab 1; Page 2/22Spring 2017
The COMTRADE file is actually threefiles. One has an extension "*.hdr". This file will be emtpy in this case. Another has theextension "*.dat". This has the actual numerical data in columns of numbers. The third file is a configuration file and has theextension "*.cfg" and this tells the program reading the numerical data what the columns represent. The configuration file providesscaling and offset information for each of the variables stored as vectors. Here is a typical entry:
1,TACS LEM6IN,,,,2.6836E-06,7.6143E-04,0.0000E00,-32765,32765,1,1,P
Each data record starts entry number (1-7 here), the name for the measurements (for example "TACS LEM6IN").
The number after the 4 commas (column 5 starting numbering with 0) is a scale factor. The next number (column 6) is an offsetfactor. If you don't change the scaling and offset factors, the waveforms you evaluate won't be correct. The MathCAD sheet hasfurther instructions.
COMTRADE configuration file format:The first fow states how the file was created and the version of the standard1.The second row gives the total number of inputs (7 for these cases), number of analog inputs (7 here) and number of digital2.inputs (0 here)Rows 3 - 10 are the analog inputs, in the following order:3.
In (referred to as residual current below)IaIbIcVanVbnVcn
4. Data sampled 16 times per cycle (960 Hz)
ECE 526: Protection of Power Systems
Lab 1; Page 3/22Spring 2017
Relay Model:
Supervisory Overcurrent Element Settings
These Instantaneous Overcurrent Elements are used to supervise the distance elements. Enter settings in secondary Amps,(again leave off units) for zero sequence (ground) and negative sequence (designated with a Q) and phase. Set theseelements to enable the distance element if the current exceeds a threshhold that ensures that it is a fault.
Enable the relay elements you want to use (1 means enabled, 0 means disabled)
E50P1 1 E50P2 1
E50G1 1 E50G2 1
Relay Pickup Settings (default values set very small)
Level_1_50P 0.5 Level_2_50P 0.5
Level_1_50G 0.5 Level_2_50G 0.5
Level 2 Time Delays Define cycles 1
TDelP 5cycles default at 5 cycles
TDelG 5 cycles
ECE 526: Protection of Power Systems
Lab 1; Page 4/22Spring 2017
Relay Overcurrent Element Pick Up Logic
Initialize overcurrent elements: Level150G_puv 0 Level250G_puv 0
Level150P_puv 0 Level250P_puv 0
Ground (zero sequence) element (using calculated instead of measured currents):
Level150G_puv 1 3 IA0v Level_1_50Gif
1 Level150G_puv 1 0.01if
0 otherwise
Level250G_puv 1 3 IA0v Level_2_50Gif
1 Level250G_puv 1 0.01if
0 otherwise
Phase current element (phase A or phase B or Phase C exceed pickup)
Level150P_puv 1 IAcpxv Level_1_50Pif
1 IBcpxv Level_1_50Pif
1 ICcpxv Level_1_50Pif
1 Level150P_puv 1 0.01if
0 otherwise
Level250P_puv 1 IAcpxv Level_2_50Pif
1 IBcpxv Level_2_50Pif
1 ICcpxv Level_2_50Pif
1 Level250P_puv 1 0.01if
0 otherwise
ECE 526: Protection of Power Systems
Lab 1; Page 5/22Spring 2017
0 5 100
2
4
6
8
10
IAcpxv
IBcpxv
ICcpxv
Level_1_50P
Level_2_50P
v
RS
Relay Response
Phase Currents
Ground current
ECE 526: Protection of Power Systems
Lab 1; Page 6/22Spring 2017
0 5 100
2
4
6
IA0v
Level_1_50G
Level_2_50G
v
RS
Relay overcurrent element pick up (without time delays)
0 5 100
0.5
1
1.5
Level150P_puv
Level250P_puv
v
RS
ECE 526: Protection of Power Systems
Lab 1; Page 7/22Spring 2017
0 5 100
0.5
1
1.5
Level150G_puv
Level250G_puv
v
RS
Relay Distance Element Settings
Line impedance in Ohm's secondary (i.e. values seen after the CTR and PTR are factored in).
Z1 2 j 18
Z0 3 Z1
θline arg Z1( ) arg Z1( ) 83.6598 deg
Z1MAG Z1 Z1ANG arg Z1( )
Z0MAG Z0 Z0ANG arg Z0( )
Here is the equation for the k0 factor. You might need to enter magnitude and angle seperately in some relays, here it is calculated bythe "relay" and used as a phasor. If k0 has been user entered, then Z0=Z1 for some relays.
ECE 526: Protection of Power Systems
Lab 1; Page 8/22Spring 2017
k0Z0 Z1
3 Z1 k0 0.6667
Distance Elements (set as percentage reach) (default values)
Zone1P 75% Zone2P 125%
Zone1G 75% Zone2G 125%
Level 2 Time Delays (default values)
TDelDP 5cycles default at 5 cycles
TDelDG 5cycles default at 5 cycles
Ground and Phase Distance Elements
Phase Elements:
Calculate Mho Circles:
θmho 0deg 0.5deg 360deg k 0 1 719
radMho1 Zone1GZ1MAG
2 radMho2 Zone2G
Z1MAG2
Note the divide by two for radius of circle
ECE 526: Protection of Power Systems
Lab 1; Page 9/22Spring 2017
offsetMho1 Zone1GZ1MAG
2
ej θline offsetMho2 Zone2G
Z1MAG2
ej θline
Again, note the divide by 2
Zone1k offsetMho1 radMho1 ej k 0.5 deg
Zone2k offsetMho2 radMho2 ej k 0.5 deg
centerMho2_G Zone2GZ12
centerMho1_G Zone1GZ12
centerMho2_P Zone2PZ12
centerMho1_P Zone1PZ12
Convert line impedance into a vector for comparison purposes:
LineZ0
Z1
Ground Elements:
Now calculate impedance seen by the relay. Note that this approach will have problems for a close-in faultwhere the voltage falls.Also note that k0 is multiplied times the residual current (this model uses IR and has a 1/3 in the k0 calculationon page 187 in Blackburn).
ECE 526: Protection of Power Systems
Lab 1; Page 10/22Spring 2017
ZAGv
VAcpxv
IAcpxv k0 IRcpxv RAGv Re ZAGv XAGv Im ZAGv
ZBGv
VBcpxv
IBcpxv k0 IRcpxv RBGv Re ZBGv XBGv Im ZBGv
ZCGv
VCcpxv
ICcpxv k0 IRcpxv RCGv Re ZCGv XCGv Im ZCGv
Distance Element Response in Impedance Plane
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20 0 20
10
20
30
XAGv 19
Im LineZ( )
Im Zone1k
Im Zone2k
RAGv 19 Re LineZ( ) Re Zone1k Re Zone2k
Note also that the first 19 samples are ignored, since the Z is huge until the filtered current increases from 0
ECE 526: Protection of Power Systems
Lab 1; Page 12/22Spring 2017
20 0 20
10
20
30
XBGv 19
Im LineZ( )
Im Zone1k
Im Zone2k
RBGv 19 Re LineZ( ) Re Zone1k Re Zone2k
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Lab 1; Page 13/22Spring 2017
20 0 20
10
20
30
XCGv 19
Im LineZ( )
Im Zone1k
Im Zone2k
RCGv 19 Re LineZ( ) Re Zone1k Re Zone2k
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Lab 1; Page 14/22Spring 2017
Now use the m-equations to get more of a picture of the time response:
Leave self polarized for now:
VPOLVai VAcpxi VPOLVbi VBcpxi VPOLVci VCcpxi
MAGi
Re VAcpxi VPOLVai
Re 1 ej Z1ANG IAcpxi k0 IRcpxi VPOLVai
.00001
MBGi
Re VBcpxi VPOLVbi
Re 1 ej Z1ANG IBcpxi k0 IRcpxi VPOLVbi
.00001
MCGi
Re VCcpxi VPOLVci
Re 1 ej Z1ANG ICcpxi k0 IRcpxi VPOLVci
.00001
0 5 100
10
20MAGv
MBGv
MCGv
Zone1G Z1MAG
Zone2G Z1MAG
v
RS
ECE 526: Protection of Power Systems
Lab 1; Page 15/22Spring 2017
Phase to Ground Distance Element Pickup Logic
Since the graphical representation is not very precise, define more exact equations:
Initialize Elements: Level121DG_puv 0 Level221DG_puv 0
Level121DG_puIf 1 ZAGIf centerMho1_G radMho1if
1 ZBGIf centerMho1_G radMho1if
1 ZCGIf centerMho1_G radMho1if
1 Level121DG_puIf 1 0.01if
0 otherwise
Level221DG_puIf 1 ZAGIf centerMho2_G radMho2if
1 ZBGIf centerMho2_G radMho2if
1 ZCGIf centerMho2_G radMho2if
1 Level221DG_puIf 1 0.01if
0 otherwise
Next semester we will add fault type identifcation logic to limit the elements used to restrict the active element to the faultedphases to increase security
Relay ground distance element pick up (without time delays)
0 5 100
0.5
1
1.5
Level121DG_puIf
Level221DG_puIf
If
RS
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Lab 1; Page 16/22Spring 2017
Phase to phase elements:
ZABPv
VAcpxv VBcpxv
IAcpxv IBcpxv 0.0001 RABPv Re ZABPv XABPv Im ZABPv
ZBCPv
VBcpxv VCcpxv
IBcpxv ICcpxv 0.0001 RBCPv Re ZBCPv XBCPv Im ZBCPv
ZCAPv
VCcpxv VAcpxv
ICcpxv IAcpxv 0.0001 RCAPv Re ZCAPv XCAPv Im ZCAPv
20 0 20
10
20
30
XABPv 19
Im Zone1k
Im Zone2k Im LineZ( )
RABPv 19 Re Zone1k Re Zone2k Re LineZ( )
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20 0 20 40
10
20
30
40
XBCPv 19
Im Zone1k
Im Zone2k Im LineZ( )
RBCPv 19 Re Zone1k Re Zone2k Re LineZ( )
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20 0 20
10
20
30
XCAPv 19
Im Zone1k
Im Zone2k Im LineZ( )
RCAPv 19 Re Zone1k Re Zone2k Re LineZ( )
ECE 526: Protection of Power Systems
Lab 1; Page 19/22Spring 2017
Again, use the "m"equations to see the timing: MABi
Re VAcpxi VBcpxi VPOLVai VPOLVbi
Re 1 ej Z1ANG IAcpxi IBcpxi VPOLVai VPOLVbi
.00001
MBCi
Re VBcpxi VCcpxi VPOLVbi VPOLVci
Re 1 ej Z1ANG IBcpxi ICcpxi VPOLVbi VPOLVci
.00001
MCAi
Re VCcpxi VAcpxi VPOLVci VPOLVai
Re 1 ej Z1ANG ICcpxi IAcpxi VPOLVci VPOLVai
.00001
0 5 10 150
10
20MABv
MBCv
MCAv
Zone1P Z1MAG
Zone2P Z1MAG
v
RS
ECE 526: Protection of Power Systems
Lab 1; Page 20/22Spring 2017
Phase to Phase Distance Element Pickup Logic
Initialize Elements: Level121DP_puv 0 Level221DP_puv 0
Level121DP_puIf 1 ZABPIf centerMho1_P radMho1if
1 ZBCPIf centerMho1_P radMho1if
1 ZCAPIf centerMho1_P radMho1if
1 Level121DP_puIf 1 0.01if
0 otherwise
Level221DP_puIf 1 ZABPIf centerMho2_P radMho2if
1 ZBCPIf centerMho2_P radMho2if
1 ZCAPIf centerMho2_P radMho2if
1 Level221DP_puIf 1 0.01if
0 otherwise
Relay phase distance element pick up (without time delays)
0 5 100
0.5
1
1.5
Level121DP_puIf
Level221DP_puIf
If
RS
ECE 526: Protection of Power Systems
Lab 1; Page 21/22Spring 2017
Trip Logic
Note that logic AND is Ctrl + shift + 7, the logic OR is Ctrl + shift + 6, the logic not is Ctrl + shift +1.
Level250P_pu DelP0
DelP0
E50P1
Level150P_pu
Zone121DP_pu
E50P2
TRP
Zone221DP_pu
Level150G_pu
DelP0
DelP0
TRG
E50G2
E50G1
Zone221DG_pu
Level250G_pu
Zone121DG_pu
TRG TRIPTRP
TRPd E50P1 Level150P_pud Level121DP_pud E50P2 Level250P_pud TDelP RS Level221DP_pud TDelDP RS
Note that this includes the time delay for level 2
TRGd E50G1 Level150G_pud Level121DG_pud E50G2 Level250G_pud TDelG RS Level221DG_pud TDelDG RS
Overall Trip Equation:
Tripv TRPv TRGv
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Lab 1; Page 22/22Spring 2017
0 5 100
0.5
1
1.5
TRPv
TRGv
v
RS
Trip equation response
0 5 100
0.5
1
1.5
Tripv
v
RS
Final trip equation