Distance Relay Model - uidaho.edu · Distance Relay Model ... This has the actual numerical data in columns of numbers. ... Relay Distance Element Settings

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)



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)



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



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



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



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



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.



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



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).



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



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



20 0 20

10

20

30

XBGv 19

Im LineZ( )

Im Zone1k

Im Zone2k

RBGv 19 Re LineZ( ) Re Zone1k Re Zone2k



20 0 20

10

20

30

XCGv 19

Im LineZ( )

Im Zone1k

Im Zone2k

RCGv 19 Re LineZ( ) Re Zone1k Re Zone2k



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



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



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( )



20 0 20 40

10

20

30

40

XBCPv 19

Im Zone1k


RBCPv 19 Re Zone1k Re Zone2k Re LineZ( )



20 0 20

10

20

30

XCAPv 19

Im Zone1k


RCAPv 19 Re Zone1k Re Zone2k Re LineZ( )



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



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



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



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

Documents

Distance Relay Model - uidaho.edu · Distance Relay Model ... This has the actual numerical data in columns of numbers. ... Relay Distance Element Settings