Communication-Assisted Transfer Trip Schemes · Communication-Assisted Transfer Trip Schemes The MathCAD sheet below implements some basic relay calculations. The file takes data

ECE 526: Protection of Power Systems II

Session 17; Page 1/25Spring 2017

Communication-Assisted Transfer Trip Schemes

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.

Part 1. Read Comtrade File Data

1. Read Comtrade Configuration File:

config...\SLG25R10.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). MathCAD 13 or higherusers, right click and select properties.

data...\SLG25R10.dat

Right click on the floppy disk icon and select "Choose File" toopen a file browser. Choose the *.dat file from the contrade file (itshould be an accepted file type)



COMTRADE configuration file format:The first row (row 0) states how the file was created and the version of the standard1.The second row (row 1) gives the total number of inputs (14 for these cases), number of analog inputs (14 here) and number2.of digital inputs (0 here)Rows 2-8 are the analog inputs for relay 1 in this model, in the following order:3.

In (referred to as residual current below)IaIbIcVan at Bus 1VbnVcn

Rows 9-15 are the analog inputs for relay 2 in this model, in the following order:In (referred to as residual current below)IaIbIcVan at Bus 2VbnVcn

4. Data sampled 16 times per cycle (960 Hz)

User Entered Parameters:I am entering typical values the current transformer ration (CTR) and voltage transformer ratio (PTR). You need to change theseto match your calculations.

CTR 1 PTR 1 Same for both relay modelsSampling rate (samples/sec) RS 16

Click on the Arrow to hide/unhide the digital filtering, angle calculations and symmterical components calculations

Now plot the currents and voltages. These should be sinusoidal. Note that the horizontal axis is in the number of cycles since thei/RS is sample number divided by sampling rate.

As a check, the prefault data should be balanced three phase



Relay 1 phase currents and residual current

0 5 1010

5

0

5

10

IA_r1i

IB_r1i

IC_r1i

IR_r1i

i

RS

0 5 10300

200

100

0

100

200

300

VA_r1i

VB_r1i

VC_r1i

i

RS

0 5 100

50

100

150

VA0_r1v

VA1_r1v

VA2_r1v

v

RS

0 5 100

1

2

3

IA0_r1v

IA1_r1v

IA2_r1v

v

RS



0 5 100

2

4

6

8

3 IA0_r1v

IR_r1cpxv

v

RS

Compare 3I0 to measured residual (ground current)

Relay 2 phase currents and residual current Relay 2 line to ground voltages:



0 5 103

2

1

0

1

2

3

IA_r2i

IB_r2i

IC_r2i

IR_r2i

i

RS

0 5 10300

200

100

0

100

200

300

VA_r2i

VB_r2i

VC_r2i

i

RS

Symmetrical Components: phasor with magnitude and phase (we are only uses magnitude for now).



0 2 4 6 8 10 120

2

4

6

8

IA_r1cpxv

IB_r1cpxv

IC_r1cpxv

IR_r1cpxv

v

RS

0 2 4 6 8 10 120

30

60

90

120

150

VA_r1cpxv

VB_r1cpxv

VC_r1cpxv

v

RS

Part 2. Relay Model and Relay Settings

Relay Enable-Element Settings

Instantaneous Overcurrent Elements (secondary Amps, again leave off units) for zero sequence (ground) and negativesequence (designated with a Q). elements. These numbers are just made up so don't base your answers on these. Usemagnitudes from the phase A components.

Enable the relay elements you want to use (1 means enabled, 0 means disabled)

Relay 1 Relay 2



E50P1_r1 1 E50P2_r1 1 E50P1_r2 1 E50P2_r2 1

E50Q1_r1 1 E50Q2_r1 1 E50Q1_r2 1 E50Q2_r2 1

E50G1_r1 1 E50G2_r1 1 E50G1_r2 1 E50G2_r2 1

Relay Pickup Settings

Overcurrent element settings for Relay1 and Relay 2 (Overcurrent elements work as fault detectors in the relay model)

Relay 1 Relay 2

Level_1_50P_r1 6.6 Level_2_50P_r1 1.5 Level_1_50P_r2 1 Level_2_50P_r2 0.5

Level_1_50Q_r1 3.3 Level_2_50Q_r1 0.6 Level_1_50Q_r2 1 Level_2_50Q_r2 0.5

Level_1_50G_r1 1.4 Level_2_50G_r1 0.60 Level_1_50G_r2 1 Level_2_50G_r2 0.5

Level 2 Time Delay Setting for Relay 1 and Relay 2

Define cycles 1 ( Do not change these Time Delay values. )

Relay 1 Relay 2

TDelP_r1 5cycles TDelP_r2 5cycles

TDelQ_r1 5cycles TDelQ_r2 5cycles

TDelG_r1 5 cycles TDelG_r2 5 cycles

Distance Element Setting for Relay 1 and Relay 2



Line impedance in Ohm's secondary (i.e. values seen after the CTR and PTR are factored in). Change to match system you are modeling

Relay 1

Z1_r1 10.05ej 84 deg Z1MAG_r1 Z1_r1 Z1MAG_r1 10.05

Z1ANG_r1 arg Z1_r1( ) Z1ANG_r1 84 deg

Z0_r1 3 Z1_r1 Z0MAG_r1 Z0_r1 Z0MAG_r1 30.15


Relay 2

Z1_r2 10.05ej 84 deg Z1MAG_r2 Z1_r2 Z1MAG_r2 10.05


Z0_r2 3 Z1_r2 Z0MAG_r2 Z0_r2 Z0MAG_r2 30.15


Here is the equation for the k0 factor. You might need to enter magnitude and angle seperately in some relays, here it is used as a phasor.

Relay 1 Relay 2

k0_r1Z0_r1 Z1_r1

3 Z1_r1 k0_r1 0.6667 k0_r2

Z0_r2 Z1_r2

3 Z1_r2 k0_r2 0.6667

Distance Elements Settings (set as percentage reach) (default values - change as appropriate)



Relay 1 Relay 2

Zone1P_r1 80% Zone1P_r2 80%

Zone1G_r1 80% Zone1G_r2 80%

Zone2P_r1 150% Zone2P_r2 150%

Zone2G_r1 200% Zone2G_r2 200%

Level 2 Time Delays (default values) ( Do not change these Time Delay values. )

Relay 1 Relay 2TDelDP_r1 5cycles TDelDP_r2 5cycles default at 5 cyclesdefault at 5 cycles

TDelDG_r1 5cycles TDelDG_r2 5cycles default at 5 cyclesdefault at 5 cycles

Ground and Phase Distance Elements

Phase Elements (Relay 1)θmho 0deg 0.5deg 360deg k 0 1 719

radMho1P_r1 Zone1P_r1Z1MAG_r1

2 radMho2P_r1 Zone2P_r1

Z1MAG_r12

radMho1G_r1 Zone1G_r1Z1MAG_r1

2 radMho2G_r1 Zone2G_r1

Z1MAG_r12

Note the divide by two for radius of circle



centerMho1_P_r1 Zone1P_r1Z1_r1

2 centerMho2_P_r1 Zone2P_r1

Z1_r12

centerMho1_G_r1 Zone1G_r1Z1_r1

2 centerMho2_G_r1 Zone2G_r1

Z1_r12

Zone1MhoP_r1k centerMho1_P_r1 radMho1P_r1 ej k 0.5 deg


Zone1MhoG_r1k centerMho1_G_r1 radMho1G_r1 ej k 0.5 deg


LineZG_r10

Z1_r1

LineZP_r10

Z1_r1

ZABP_r1v

VA_r1cpxv VB_r1cpxv

IA_r1cpxv IB_r1cpxv RABP_r1v Re ZABP_r1v XABP_r1v Im ZABP_r1v

ZBCP_r1v

VB_r1cpxv VC_r1cpxv

IB_r1cpxv IC_r1cpxv RBCP_r1v Re ZBCP_r1v XBCP_r1v Im ZBCP_r1v

ZCAP_r1v

VC_r1cpxv VA_r1cpxv

IC_r1cpxv IA_r1cpxv RCAP_r1v Re ZCAP_r1v XCAP_r1v Im ZCAP_r1v

Ground Elements (Relay 1)

ZAG_r1v

VA_r1cpxv

IA_r1cpxv k0_r1 IR_r1cpxv RAG_r1v Re ZAG_r1v XAG_r1v Im ZAG_r1v



ZBG_r1v

VB_r1cpxv

IB_r1cpxv k0_r1 IR_r1cpxv RBG_r1v Re ZBG_r1v XBG_r1v Im ZBG_r1v

ZCG_r1v

VC_r1cpxv

IC_r1cpxv k0_r1 IR_r1cpxv RCG_r1v Re ZCG_r1v XCG_r1v Im ZCG_r1v

Phase Elements (Relay 2)

radMho1P_r2 Zone1P_r2Z1MAG_r2

2 radMho2P_r2 Zone2P_r2

Z1MAG_r22

radMho1G_r2 Zone1G_r2Z1MAG_r2

2 radMho2G_r2 Zone2G_r2

Z1MAG_r22

Note the divide by two for radius of circle

centerMho1_P_r2 Zone1P_r2Z1_r2

2 centerMho2_P_r2 Zone2P_r2

Z1_r22

centerMho1_G_r2 Zone1G_r2Z1_r2

2 centerMho2_G_r2 Zone2G_r2

Z1_r22







LineZG_r20

Z1_r2

LineZP_r20

Z1_r2

ZABP_r2v

VA_r2cpxv VB_r2cpxv

IA_r2cpxv IB_r2cpxv RABP_r2v Re ZABP_r2v XABP_r2v Im ZABP_r2v

ZBCP_r2v

VB_r2cpxv VC_r2cpxv

IB_r2cpxv IC_r2cpxv RBCP_r2v Re ZBCP_r2v XBCP_r2v Im ZBCP_r2v

ZCAP_r2v

VC_r2cpxv VA_r2cpxv

IC_r2cpxv IA_r2cpxv RCAP_r2v Re ZCAP_r2v XCAP_r2v Im ZCAP_r2v

Ground Elements (Relay 2)

ZAG_r2v

VA_r2cpxv

IA_r2cpxv k0_r2 IR_r2cpxv RAG_r2v Re ZAG_r2v XAG_r2v Im ZAG_r2v

ZBG_r2v

VB_r2cpxv

IB_r2cpxv k0_r2 IR_r2cpxv RBG_r2v Re ZBG_r2v XBG_r2v Im ZBG_r2v

ZCG_r2v

VC_r2cpxv

IC_r2cpxv k0_r2 IR_r2cpxv RCG_r2v Re ZCG_r2v XCG_r2v Im ZCG_r2v



Relay Element Pick Up Logic

Initialize Relay Element Terms (use I2 and I0, not 3*I2 and 3*I0)

Relay 1 Relay 2

Level1Q_r1_puv 0 Level2Q_r1_puv 0 Level1Q_r2_puv 0 Level2Q_r2_puv 0

Level1G_r1_puv 0 Level2G_r1_puv 0 Level1G_r2_puv 0 Level2G_r2_puv 0

Level1P_r1_puv 0 Level2P_r1_puv 0 Level1P_r2_puv 0 Level2P_r2_puv 0

Level1DP_r1_puIf 0 Level2DP_r1_puIf 0 Level1DP_r2_puIf 0 Level2DP_r2_puIf 0

Level1DG_r1_puIf 0 Level2DG_r1_puIf 0 Level1DG_r2_puIf 0 Level2DG_r2_puIf 0

Part 3. Relay 1 pickup logic and trip equations

Negative sequence element (modified to latch and stay one, no drop out for now)

Level1Q_r1_puv 1 IA2_r1v Level_1_50Q_r1if

1 Level1Q_r1_puv 1 0.01if

0 otherwise



0 otherwise

Ground (zero sequence) element (using calculated instead of measured currents):

Level1G_r1_puv 1 IA0_r1v Level_1_50G_r1if

1 Level1G_r1_puv 1 0.01if

0 otherwise



0 otherwise



Phase current element (phase A or phase B or Phase C exceed pickup)

Level1P_r1_puv 1 IA_r1cpxv Level_1_50P_r1if

1 IB_r1cpxv Level_1_50P_r1if

1 IC_r1cpxv Level_1_50P_r1if

1 Level1P_r1_puv 1 0.01if

0 otherwise





0 otherwise

Phase Distance Element Pickup Logic

Level1DP_r1_puIf 1 ZABP_r1If centerMho1_P_r1 radMho1P_r1if

1 ZBCP_r1If centerMho1_P_r1 radMho1P_r1if

1 ZCAP_r1If centerMho1_P_r1 radMho1P_r1if

1 Level1DP_r1_puIf 1 0.01if

0 otherwise





0 otherwise



20 10 0 10 20

10

20

XABP_r1v 19

XBCP_r1v 19

XCAP_r1v 19

Im LineZP_r1( )

Im Zone1MhoP_r1k Im Zone2MhoP_r1k

RABP_r1v 19 RBCP_r1v 19 RCAP_r1v 19 Re LineZP_r1( ) Re Zone1MhoP_r1k Re Zone2MhoP_r1k

Ground Distance Element Pickup LogicLevel1DG_r1_puIf 1 ZAG_r1If centerMho1_G_r1 radMho1G_r1if

1 ZBG_r1If centerMho1_G_r1 radMho1G_r1if

1 ZCG_r1If centerMho1_G_r1 radMho1G_r1if

1 Level1DG_r1_puIf 1 0.01if

0 otherwise

Level2DG_r1_puIf 1 ZAG_r1If centerMho2_G_r1 radMho2G_r1if




0 otherwise



20 10 0 10 20

10

20

XAG_r1v 19

XBG_r1v 19

XCG_r1v 19

Im LineZG_r1( )

Im Zone1MhoG_r1k Im Zone2MhoG_r1k

RAG_r1v 19 RBG_r1v 19 RCG_r1v 19 Re LineZG_r1( ) Re Zone1MhoG_r1k Re Zone2MhoG_r1k

Relay 2 pickup logic and trip equations:

Negative sequence element (modified to latch and stay one, no drop out for now)



0 otherwise



0 otherwise



Ground (zero sequence) element (using calculated instead of measured currents):



0 otherwise



0 otherwise

Phase current element (phase A or phase B or Phase C exceed pickup)





0 otherwise





0 otherwise

Phase Distance Element Pickup Logic





0 otherwise





0 otherwise



20 10 0 10 20

10

20

XABP_r2v 19

XBCP_r2v 19

XCAP_r2v 19

Im LineZP_r2( )

Im Zone1MhoP_r2k Im Zone2MhoP_r2k

RABP_r2v 19 RBCP_r2v 19 RCAP_r2v 19 Re LineZP_r2( ) Re Zone1MhoP_r2k Re Zone2MhoP_r2k

Ground Distance Element Pickup Logic





0 otherwise





0 otherwise



20 10 0 10 20

5

5

10

15

XAG_r2v 19

XBG_r2v 19

XCG_r2v 19

Im LineZG_r2( )

Im Zone1MhoG_r2k Im Zone2MhoG_r2k

RAG_r2v 19 RBG_r2v 19 RCG_r2v 19 Re LineZG_r2( ) Re Zone1MhoG_r2k Re Zone2MhoG_r2k

Part 4. Trip Logic and Relay Response

Note that logic AND is Ctrl + shift + 7, the logic OR is Ctrl + shift + 6, the logic not is Ctrl + shift +1.

(1) Conventional Trip Logic without CommunicationRelay 1

Level2P_r1_pu_t_delayd Level2P_r1_pud TDelP_r1 RS Note that this makes the time delay for level 2

TR50P_r1v E50P1_r1 Level1P_r1_puv E50P2_r1 Level2P_r1_pu_t_delayv



Level2Q_r1_pu_t_delayd Level2Q_r1_pud TDelQ_r1 RS Note that this makes the time delay for level 2

TR50Q_r1v E50Q1_r1 Level1Q_r1_puv E50Q2_r1 Level2Q_r1_pu_t_delayv

Level2G_r1_pu_t_delayd Level2G_r1_pud TDelG_r1 RS Note that this makes the time delay for level 2

TR50G_r1v E50G1_r1 Level1G_r1_puv E50G2_r1 Level2G_r1_pu_t_delayv

TR50_r1v TR50P_r1v TR50Q_r1v TR50G_r1v

Level2DP_r1_pu_t_delayd Level2DP_r1_pud TDelDP_r1 RS Note that this makes the time delay for level 2

TR21P_r1v Level1DP_r1_puv Level2DP_r1_pu_t_delayv

Level2DG_r1_pu_t_delayd Level2DG_r1_pud TDelDG_r1 RS Note that this makes the time delay for level 2

TR21G_r1v Level1DG_r1_puv Level2DG_r1_pu_t_delayv

TR21_r1v TR21P_r1v TR21G_r1v

Relay 2

Level2P_r2_pu_t_delayd Level2P_r2_pud TDelP_r2 RS Note that this makes the time delay for level 2

TR50P_r2v E50P1_r2 Level1P_r2_puv E50P2_r2 Level2P_r2_pu_t_delayv

Level2Q_r2_pu_t_delayd Level2Q_r2_pud TDelQ_r2 RS Note that this makes the time delay for level 2

TR50Q_r2v E50Q1_r2 Level1Q_r2_puv E50Q2_r2 Level2Q_r2_pu_t_delayv



Level2G_r2_pu_t_delayd Level2G_r2_pud TDelG_r2 RS Note that this makes the time delay for level 2

TR50G_r2v E50G1_r2 Level1G_r2_puv E50G2_r2 Level2G_r2_pu_t_delayv

TR50_r2v TR50P_r2v TR50Q_r2v TR50G_r2v

Level2DP_r2_pu_t_delayd Level2DP_r2_pud TDelDP_r2 RS Note that this makes the time delay for level 2

TR21P_r2v Level1DP_r2_puv Level2DP_r2_pu_t_delayv

Level2DG_r2_pu_t_delayd Level2DG_r2_pud TDelDG_r2 RS Note that this makes the time delay for level 2

TR21G_r2v Level1DG_r2_puv Level2DG_r2_pu_t_delayv

TR21_r2v TR21P_r2v TR21G_r2v

Final Trip LogicTR_r1v TR21_r1v TR50_r1v

TR_r2v TR21_r2v TR50_r2v



Relay responses Remote RelayLocal Relay

0 5 100

0.5

1

1.5

TR_r1v

v

RS

0 5 100

0.5

1

1.5

TR_r2v

v

RS

(2) Direct Underreaching Transfer Trip (DUTT) Scheme

Communication Time delay: TDelComm .5cycles ( Do not change the TDelComm value )

Transmitted Signals

TRzone1_r1v E50P1_r1 Level1P_r1_puv E50Q1_r1 Level1Q_r1_puv E50G1_r1 Level1G_r1_puv Level1DP_r1_puv Level1DG_r1_puv

TX_r1v TRzone1_r1v


TX_r2v TRzone1_r2v



Received Signals (with communication time delay)TX_r2_t_delayd2 TX_r2d2 TDelComm RS Note that this makes the time delay for Communication

RX_r1v TX_r2_t_delayv

TX_r1_t_delayd2 TX_r1d2 TDelComm RS Note that this makes the time delay for Communication


Final Trip LogicTR_DUTT_r1v TRzone1_r1v RX_r1v

TR_DUTT_r2v TRzone1_r2v RX_r2v

Relay responses (observe if there is a time difference, compared to POTT or case without communication)

0 5 100

0.5

1

1.5

TR_DUTT_r1v

v

RS

0 5 100

0.5

1

1.5

TR_DUTT_r2v

v

RS



(3) Permissive Overreaching Transfer Trip (POTT) Scheme

Communication Time delay: TDelComm 0.5cycles

Transmitted Signals


TX_r1v TRzone2_r1v


TX_r2v TRzone2_r2v

Received Signals (with communication time delay)





Final Trip Logic

TR_POTT_r1v TRzone2_r1v RX_r1v

TR_POTT_r2v TRzone2_r2v RX_r2v



Relay responses

0 5 100

0.5

1

1.5

TR_POTT_r1v

v

RS

0 5 100

0.5

1

1.5

TR_POTT_r2v

v

RS

Documents

Communication-Assisted Transfer Trip Schemes · Communication-Assisted Transfer Trip Schemes The MathCAD sheet below implements some basic relay calculations. The file takes data