Testing Procedure of Sel 321 Relay - Lop

TESTING PROCEDURE FOR LOSS OF POTENTIAL (LOP), POWER SWING BLOCKING (PSB) AND SWITCH ON TO FAULT (SOTF) FEATURES OF DISTANCE PROTECTION RELAY SEL 321 USING OMICRON TEST KIT The following testing procedure elaborates testing of Loss of potential (LOP), power swing blocking (Out of step blocking - OOS) and switch on to fault (SOTF) features of SEL 321 through OMICRON test kit. This testing procedure is made with reference to some standard settings and these settings provided in the respective features. LOSS OF POTENTIAL (LOP) FEATURE: Settings Of Loss Of Potential (LOP):

ELOP LOPD 50M 59NL 59PL

=Y = 1.00 = 0.20 = 15.00 = 15.00

In SEL 321 relay LOP is detected by the condition with zero sequence voltage (V0) and no zero sequence current (I0). This condition can be simulated via OMICRON Quick CMC module.

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Loss Of Potential

Step 1

Click “OMICRON Test Universe 1.51” Icon in desktop

“OMICRON start page” window opens.

Step 2

Click “QuickCMC” in “OMICRON Start Page”

“OMICRON QuickCMC” window opens.

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Step 3

In “OMICRON QuickCMC”” window select ‘Parameters > Test Object…’

“Test Object Parameters” menu window opens.

Step 4

Fill the relevant parameters for the test object and click “OK” button.

“Test Object Parameters” menu window closes.

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Step 5

In “OMICRON QuickCMC” window select ‘Parameters > Hardware Configuration…’

Step 6

In “Hardware Configuration” menu Click “General > Test Set(s) > Details”

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“Hardware Configuration” menu window opens.

“Output Configuration Details” menu window opens.

Step 7

Select 3 Voltage and 3 current sources & Click “OK” & Click “OK”.

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“Output Configuration Details” & “Hardware Configuration” are closes respectively.

Step 8

In “OMICRON QuickCMC” window select ‘View > Test’.

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“Test View” Menu opens.

Step 9

In “OMICRON QuickCMC –  {Test View: QuickCMC1” window fill the nominal voltage levels in ‘CMC256-6 Voltage A’ menu for all the phases.

Step 10

In “OMICRON QuickCMC –  {Test View: QuickCMC1” window fill the nominal current levels in ‘CMC256-6 Current A’ menu for all the phases. Select the frequency as 50Hz in ‘Frequency menu’

Step 11

Step 12

Step 13

In ‘Step > Triple’ menu select ‘CMC 256-6 V A’ and ‘Step > Quantity’ menu ‘V1’ for the reduction of Phase A voltage. In ‘Step > Size’ menu select ’63.5 V’ and ‘Step > Time’ menu ‘1 Sec’ for the reduction of voltage and time step.

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e.g.: 63.5 V {Phase to neutral voltage} Van = 63.5 V Vbn = 63.5 V Vcn = 63.5 V e.g.: 1A. Ia = 1A Ib = 1A Ic = 1A -

Through this selection A  phase voltage can be reduced for LOP pickup. -

Step 14

In ‘Step > Auto Step’ menu Click & Select for auto reduction of voltage.

Step 15

Click the ‘Power On’ button and Down arrow button in ‘Step’ menu.

Step 16

Observe for the LOP or ILOP word bit assigned output contact closing in SEL 321 relay and note down corresponding voltages and current values in all the 3  phases.

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Through this selection voltages or currents can be automatically reduced. Voltage started to reduce in 1 V steps in 1 secs interval.

LOP or ILOP word bit should be programmed to any one of output contact.