transformer protection commissioning tools

Transformer Differential ProtectionCommissioning Tools

TransformerDifferential Protection System

Commissioning Tools

TransformerDifferential Protection System

Commissioning Tools

Transformer Differential ProtectionCommissioning Tools

Advanced Metering- Sequence components for all windings

Positive, negative and zeroRestraint and differential currents

Vector Metering- Uncompensated

Raw signal- Compensated

Post vector and ratio corrections

Digital Oscillography- All winding currents

Commissioning Tools

Transformer Differential ProtectionCommissioning Tools

Verifies Relay System Performs as per the Design.

Injection of Current and Voltage to Verify Relay Settings.

Verify proper relay Inputs and Outputs.

Verify Proper Trip Logic.

Verify Tripping and Targets.

Commissioning Testing

Transformer Differential ProtectionCommissioning Tools

Verifies In-Service Relay System is Working Properly.

Done Periodically.

E-M and Static Relays Repeat Commissioning Test.

Digital Relays Require Less Extensive Testing.

Maintenance Testing

Transformer Differential ProtectionCommissioning Tools

Y-Y-Y, yyy, normal load flow

Y-Y-Y, yyy, rolled phase on W2

Δ-Y-Y, yyy, normal load flow

Δ-Y-Y, yyy, rolled phase on W1

Commissioning Examples

Transformer Differential ProtectionCommissioning Tools

Test equipment is used to simulate 3-winding transformers of various winding and CT configurations

Injected 3A into W1, injected 1.5A into W2 and W3 to simulate load flow

Assumed 1:1 transformer and 1:1 CTs for simplicity

Created correct “base case”

Created incorrect case

Used advanced protection system tools to “diagnose” the incorrect connections

Details

Transformer Differential ProtectionCommissioning Tools

Y:Y:Y, yyy1:1 Transformer Ratio

1:1 CTs, Normal

Y:Y:Y, yyy1:1 Transformer Ratio

1:1 CTs, Normal

Transformer Differential ProtectionCommissioning Tools

Three Line:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Normal

Transformer Differential ProtectionCommissioning Tools

0.0

0.0

High level of positivesequence current

Low levels of negative and zero sequence current

Advanced Metering:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Normal

Transformer Differential ProtectionCommissioning Tools

Very high restraintcurrent

Very low differential current

Advanced Metering:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Normal

Transformer Differential ProtectionCommissioning Tools

W1, Phase A at 0 degreesW2, Phase A at 180 degreesW3, Phase A at 180 degrees

W1, Phase A at 0 degreesW2, Phase A at 180 degreesW3, Phase A at 180 degrees

Vector Metering:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Normal

Transformer Differential ProtectionCommissioning Tools

W1, Phase A

W2, Phase AW3, Phase A

Analog Traces

Digital Oscillography:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Normal

Transformer Differential ProtectionCommissioning Tools

W1, Phase A

W2, Phase AW3, Phase A

3 = (-1.5) + (-1.5)

RMS

Digital Oscillography:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Normal

Transformer Differential ProtectionCommissioning Tools

Y:Y:Y, yyy

1:1 Transformer Ratio

1:1 CTs

Roll ØA, W2

Y:Y:Y, yyy

1:1 Transformer Ratio

1:1 CTs

Roll ØA, W2

Transformer Differential ProtectionCommissioning Tools

Three Line:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Roll ØA, W2

Transformer Differential ProtectionCommissioning Tools

0.0

0.0

High level of positivesequence current

Levels of negative and zero sequence current,Positive sequence current not at phase current level

Advanced Metering:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Roll ØA, W2

Transformer Differential ProtectionCommissioning Tools

Restraint current lessthan through current

High differential current

Advanced Metering:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Roll ØA, W2

Transformer Differential ProtectionCommissioning Tools

W1, Phase A at 0 degreesW2, Phase A at 0 degrees (180)

W3, Phase A at 180 degrees

W1, Phase A at 0 degreesW2, Phase A at 0 degrees (180)

W3, Phase A at 180 degrees

Vector Metering:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Roll ØA, W2

Transformer Differential ProtectionCommissioning Tools

W1, Phase AW2, Phase A

W2, Phase AW3, Phase A

Differential Trip

Analog Traces

Digital Oscillography:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Roll ØA, W2

Transformer Differential ProtectionCommissioning Tools

W1, Phase AW2, Phase A

W2, Phase AW3, Phase A

3 = (-1.5) + (-1.5)

Differential Trip

RMS

Digital Oscillography:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Roll ØA, W2

Transformer Differential ProtectionCommissioning Tools

∆:Y:Y, yyy

1:1 Transformer Ratio

1:1 CTs, Normal

∆:Y:Y, yyy

1:1 Transformer Ratio

1:1 CTs, Normal

Transformer Differential ProtectionCommissioning Tools

Three-Line:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Normal

Transformer Differential ProtectionCommissioning Tools

0.0

0.0

High level of positivesequence current

Low levels of negative and zero sequence current

Advanced Metering:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Normal

Transformer Differential ProtectionCommissioning Tools

Very high restraintcurrent

Very low differential current

Advanced Metering:Y:Y:Y, 1:1 Ratio, 1:1 CTs, Normal

Transformer Differential ProtectionCommissioning Tools

W1, Phase A at 0 degreesW2, Phase A at 30 degreesW3, Phase A at 30 degrees

W1, Phase A at 0 degreesW2, Phase A at 180 degreesW3, Phase A at 180 degrees

Phaser Metering:∆:Y:Y, 1:1 Ratio, 1:1 CTs, Normal

Transformer Differential ProtectionCommissioning Tools

W1, Phase A

W2, Phase AW3, Phase A

Analog Traces

Digital Oscillography:∆:Y:Y, 1:1 Ratio, 1:1 CTs, Normal

Transformer Differential ProtectionCommissioning Tools

∆:Y:Y, yyy

1:1 Transformer Ratio

1:1 CTs

Roll A-∆

∆:Y:Y, yyy

1:1 Transformer Ratio

1:1 CTs

Roll A-∆

Transformer Differential ProtectionCommissioning Tools

Three Line:∆:Y:Y, 1:1 Ratio, 1:1 CTs, Roll A-∆

Transformer Differential ProtectionCommissioning Tools

0.0

0.0

Levels of negative and zero sequence current,Positive sequence current not at phase current level

High level of positive sequence current

Advanced Metering:∆:Y:Y, 1:1 Ratio, 1:1 CTs, Roll A-∆

Transformer Differential ProtectionCommissioning Tools

Restraint current lessthan through current

High differential current

Advanced Metering:∆:Y:Y, 1:1 Ratio, 1:1 CTs, Roll A-∆

Transformer Differential ProtectionCommissioning Tools

W1, Phase A at 0 degrees (180)W2, Phase A at 210 degreesW3, Phase A at 210 degrees

W1, Phase A at 0 degrees (180)W2, Phase A at 0 degreesW3, Phase A at 0 degrees

Vector Metering:∆:Y:Y, 1:1 Ratio, 1:1 CTs, Roll A-∆

Transformer Differential ProtectionCommissioning Tools

W1, Phase A

W2, Phase AW3, Phase A

Differential Trip

Analog Traces

Digital Oscillography:∆:Y:Y, 1:1 Ratio, 1:1 CTs, Roll A-∆

©2008 Beckwith Electric Co., Inc.