61457757 Testing of Distnce Relay Rel 670

TESTING OF DISTNCE RELAY REL 670 1-FIRST: GENERAL EQUATION FOR ZONE REACH: The line distance protection is a five zone full scheme protection with three fault loops for phase To phase faults and three fault loops for phase to earth fault for each of the independent zones. So we will put the equation for these fault loops for phase to phase and phase to earth This figure gives: Typical quadrilateral distance protection zone with load encroachment function Activated.

**.Now we have the figures for Phase to Phase & Phase to Earth: So from the figure we can see that the reach of X axis is (X1+Xn) And R axis is equal to (RFPE).

1-X PH-E= (2X1+X0) ∗ CTR/VTR 3 2-R PH-E= RFPE

∗ CTR/VTR

3-Angle for PH-E= Arc tan

X0+2X1 R0+2R1

Fig 2: Characteristic for the phase-to-earth measuring loops, ohm/loop domain.

1-X PH-PH= X1

∗ CTR/VTR

2-R PH-PH= RFPP ∗ CTR/VTR 2 3-Angle for PH-PH= Arc tan

X1 R1

Fig 3: Characteristic for the phase-to-phase measuring loops, ohm/loop domain.

SO the complete set for these equations will be as follows: = (2X1+X0) ∗ CTR/VTR 3 2- X PH-PH = X1 ∗ CTR/VTR 1- X PH-E

3- R PH-E

=

4- R PH-PH =

RFPE

∗ CTR/VTR

RFPP ∗ CTR/VTR 2

5-Angle for PH-E= Arc tan 6-Angle for PH-PH= Arc tan

X0+2X1 R0+2R1 X1 R1

NOTE: All the previous equation is multiplied by the factor of CTR/VTR because all setting values Are entered in primary values and so as to convert it to secondary values we are using the previous Formula .

HOW TO DRAW THE REFERENCE GRAPH OF ZONES: Due to that there is no SVT tools for drawing the RIO file of the relay we are using the previous Equations to draw the reference by the aid of FREEJA program and this is specially by reference Graph editor. 1-but we have to know first the characteristics of the relay before drawing the file.

-All time in the setting it is using by default: Arg Dir

= 15°

Arg NegRes = 115°

FIG 4

-- In the figure it is shown that from the previous calculation we have drawn the Following curve by knowing the values of X axis & R axis and also by knowing the Values of Arg Dir & Arg NegRes

FIG 5 2- SECOND: GENERAL EQUATION FOR PHASE SELECTION REACH:

1-Equation for PH-E :

1-R (FWD) = RFFWPE∗CTR/VTR 2-R (REV) = RFRVPE∗CTR/VTR 3-X (FWD) = (X1+XN) ∗CTR/VTR 4-X (REV) = (X1+XN) ∗CTR/VTR

FIG 6: Characteristic of PHS for phase to earth fault (setting parameters in italic). Ohm/loop domain.

NOTE: For drawing of the reference graph we have two fixed angle equal :60° and two fixed equals 90° And this clear from the above figure.

2-Equation for PH-PH: 1-R (FWD) = 0.5 ∗ RFFWPP∗CTR/VTR 2-R (REV) = 0.5 ∗ RFRVPP∗CTR/VTR

3-X (FWD) = X1 ∗CTR/VTR 4-X (REV) = X1 ∗CTR/VTR

fig 7

NOTE: For drawing of the reference graph we have two fixed angle equal :60° and two fixed equals 90° And this clear from the above figure. And this is same like PH-E

Three phase faults: The operation condition for three phase faults is the same as for phase-to-phase fault i.e. However, the reach is expanded by a factor 2/√3 (approximately 1.1547) in all directions. At the Same time the apparent impedance is rotated 30 degrees, counter-clockwise. The characteristic Is shown in the figure:

3

2 4 1 5

6 fig 8 FOR SIMPLICITY WE CAN DRAW THE REF GRAPH BY THE AID OF SIX CIRCULES AT THE FIG: 1-∠ 120 R= 2/3 RFFWPP 2-∠ 90

R= 0.5 RFFWPP

3-∠ 30+180

X= 4/3 X1

4-∠ 120+180

R= -2/3 RFRVPP

5-∠ 90+180

R= -0.5 RFRVPP

6-∠ 30

X= -2/3 RFRVPP

fig 9 3- THIRD: GENERAL EQUATION FOR POWER SWING REACH:

Figure 10: Operating characteristic for the PSD function

1-R inner =R inner (FWD) ∗CTR/VTR

1-R outer =R inner (FWD) +ΔFW

2-R inner =R inner (REV) ∗CTR/VTR

2- R outer =R inner (REV) +ΔRV

3-X inner =X inner (FWD) ∗CTR/VTR

3- X outer =X inner (FWD) +ΔFW

4-X inner =X inner (REV) ∗CTR/VTR

4- X outer =X inner (REV) +ΔRV

Where: 1-ΔFw = RLdOutFw - KLdRFw · RLdOutFw 2-ΔRv = RLdOutRv - KLdRRv · RLdOutRv NOTE: The value of ΔFW & ΔRv all time is less than 1 4-FUNCTION TEST OF THE RELAY:

1-POWER SWING DETECTION:

Fig: the logic diagram of PSD 1-Power swing block test: from the previous test we have done the reach test of the power swing function And now we know the values of inner & outer values of PSD. So for checking the block time of PSD and for example we are putting it to Be 2 SEC. We can follow the following Procedures. **.by using general test in Freja:( automatic sequence) 1-Seq 1: Put normal Zone out of the reach of outer zone for PSD (with time 100 ms). 2-Seq 2: Put this to be in between the inner & outer zone and this with time 2000ms (blocking time). 3-Seq 3: Put this to the value of tripping zone and i.e. to be ZONE 1 with time of 100 ms and at this Seq. put the contact to trip of goal for knowing the function will trip or not. 4- At the relay and from signal matrix, put one LED to be PSD detection. 5- In the sequence test we can use the timer of the sequence to calculate the time of blocking, but this is Not accurate method because it’s giving the time more than the value of blocking by noticed amount. 6- So we can use Dual timer (external timer) to measure this time and this by applying 1-one contact for PSD detect (this will be the start contact for the timer). 2-the second contact is DIST trip (this will be the stop contact for the timer). 7- After checking the blocking time, now we can check the blocking feature of the PSD. i- From the Sequence test we can adjust the time of the second Seq. to be 1000 ms and so that the relay will remain in the blocking mode and there is now trip, Because the tripping sequence finish before the blocking time of the PSD, And so on for all z 2- SWITCH ON TO FAULT (SFV1)

Figure: SFV1 function block

This feature can be initiated by two ways (Externally & internally). And so that we will check as follow: External SOTF: 12345-

Assign one binary input to be Manual Close in the signal matrix. Assign one Led for SOTF function in the signal matrix. At the same time assign AutoIni to be off in the parameter setting. Inject from RX of the Freja manual and put tripping value like the tripping value of Zone 1. Note that injection should be done with the same time .