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Doble Turns Ratio Test: Together We Power The World

This document provides instructions for using a Doble turns ratio test (TTR) instrument to measure the ratio and capacitance of transformer windings. It explains key terminology used in the tests, such as test potential (V1), secondary voltage (V2), true capacitance (CTRUE), and apparent capacitance (CAPPARENT). The document outlines how to calculate the true capacitance by applying the test voltage V1 and measuring the current, and how to calculate the transformer turns ratio N by dividing the primary voltage V1 by the secondary voltage V2. Finally, it includes schematics of different transformer configurations (delta-wye, wye-delta) to illustrate which windings should be tested in specific

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mwasaha
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341 views9 pages

Doble Turns Ratio Test: Together We Power The World

This document provides instructions for using a Doble turns ratio test (TTR) instrument to measure the ratio and capacitance of transformer windings. It explains key terminology used in the tests, such as test potential (V1), secondary voltage (V2), true capacitance (CTRUE), and apparent capacitance (CAPPARENT). The document outlines how to calculate the true capacitance by applying the test voltage V1 and measuring the current, and how to calculate the transformer turns ratio N by dividing the primary voltage V1 by the secondary voltage V2. Finally, it includes schematics of different transformer configurations (delta-wye, wye-delta) to illustrate which windings should be tested in specific

Uploaded by

mwasaha
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
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Knowledge Is Power

Together We Power
Apparatus Maintenance and Power Management
The World for Energy Delivery

Doble Turns Ratio Test


Terminology
• V1=Test potential supplied by the instrument
• V2=Voltage on secondary winding with V1
applied to primary
• CTRUE
Capacitance measurement by instrument with
V1 applied across the capacitor
• CAPPARENT
Capacitance measurement by instrument with
V2 applied across the capacitor and the output
voltage of the instrument is V1
• N=Ratio of primary to secondary turns V1/V2
• ω=2πƒ
True Capacitance Measurement
Doble TTR
HV Lead Capacitor

V1

UST I1

LV Lead
I1
V = IZ V1 =
ωCTRUE
1 I1
Z = CTRUE =
ωC ωV1
Turns Ratio Calculation
Doble TTR
HV Lead N
Capacitor

V1 V2

UST High Low


I2
LV Lead
I2
I2 C APPARENT =
V2 = ωV1
ωCTRUE
I CTRUE ωV2
CTRUE = 2 C APPARENT =
V1 ωV 2 ωV1
N=
V2 CTRUE V1
= =N
C APPARENT V2
Transformer Ratio Measurement
Three-Phase Delta-Wye Transformer
X2
H2
Remember: Observe Vector Diagram
X1
X0
H-V Lead
H3
H1
X3
UST Mode

LV Lead

Schematic for Test No. 1: H1 - H3 to X1 - X0


Transformer Ratio Measurement

H2 X2
Remember: Observe Vector Diagram

H0 X0
H-V Lead
H1 H3 X1 X3

UST Mode

L-V Lead

Schematic for Test No. 1: H1 - H0 to X1 - X0


Transformer Ratio Measurement
Three-Phase Wye-Delta Transformer
H2 X2
Remember: Observe Vector Diagram
X1
H0
H-V Lead
H1 H3
X3
UST Mode

L-V Lead

Schematic for Test No. 1: H1 - H0 to X1 - X2


Ratio Test
End of Ratio Testing

THANK YOU

ANY QUESTIONS?

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