DOWEI

CONTENTS

FOREWORD 5

1Scope 8

2Normative references 8

3Terms and Definitions 8

3.1General definitions 9

3.2Definitions related to dielectric ratings and voltages 14

3.4Definitions related to accuracy 14

3.5Definitions related to other ratings 14

3.7 Index of abbreviations 15

5Ratings 15

5.3Rated insulation levels 16

5.3.3 Other requirements for primary terminals insulation 16

5.3.5 Insulation requirements for secondary terminals 17

5.3.501 Electromagnetic unit insulation requirements 17

5.4Rated frequency 17

5.5Rated output 17

5.5.501  Rated output values 17

5.5.502  Rated thermal limiting output 18

5.5.503  Rated output values for residual voltage windings 18

5.5.504  Rated thermal limiting output for residual voltage windings 18

5.6Rated accuracy class 18

5.6.501  Accuracy requirements for measuring capacitor voltage transformer 18

5.6.502  Accuracy requirements for protective capacitor voltage transformers 19

5.501Standard values of rated voltages 20

5.501.1Rated primary voltages UPr 20

5.501.2Rated secondary voltages 20

5.501.3Rated voltages for secondary winding intended to produce a residual voltage 21

5.501.4Standard values of rated voltage factor 21

6Design and construction 22

6.1Requirements for liquids used in equipment 22

6.1.4 Liquid tightness 22

6.7Mechanical requirements 22

6.8Multiple chopped impulse on primary terminals 22

6.9Internal arc fault protection requirements 22

6.13 Markings 22

6.13.501 Terminal markings 22

6.13.502 Rating plate markings 23

Short circuit withstand capability 27

Ferro-resonance 27

General 27

Transients of ferro-resonance oscillations 27

Transient response 28

General 28

Requirements for transient response 28

Standard transient response classes 28

Requirements for carrier – frequency accessories 29

General 29

Drain coil 29

Voltage limitation device 29

7Tests 30

7.1General 30

7.1.2List of tests 30

7.1.3Sequence of tests 31

7.2Type tests 33

7.2.2Temperature-rise test 33

7.2.3Impulse voltage withstand test on primary terminals 34

7.2.4Wet test for outdoor type transformers 35

7.2.6 Test for accuracy 35

7.2.8 Enclosure tightness test at ambient temperature 37

Capacitance and tan measurement at power-frequency 37

Short-circuit withstand capability test 38

Ferro-resonance tests 39

Transient response test 39

Type test for carrier frequency accessories 41

7.3Routine tests 42

7.3.1Power-frequency voltage withstand tests on primary terminals 42

7.3.2Partial discharge measurement 44

7.3.5 Test for accuracy 44

7.3.7Enclosure tightness test at ambient temperature 46

7.3.8Pressure test for the enclosure 46

7.3.501 Ferro-resonance check 46

7.3.502  Routine tests for carrier frequency accessories 46

7.4Special tests 47

7.4.1Chopped impulse voltage withstand test on primary terminals 47

7.4.2Multiple chopped impulse test on primary terminals 47

7.4.3Measurement of capacitance and dielectric dissipation factor 47

7.4.6 Internal arc fault test 47

7.4.501 Determination of the temperature coefficient (TC) 47

7.4.502  Tightness design test of capacitor units 47

Annex 5A (normative) Typical diagrammeme of a capacitor voltage transformer 49

Annex 5B (informative)  Transient response of capacitor voltage transformer under

fault conditions 50

Annex 5C (normative) High-frequency characteristics of capacitor voltage

transformers 51

Bibliography 52

Figure 501 – Error diagram of a capacitor voltage transformer  for accuracy classes

0,2, 0,5 and 1,0 19

Figure 502 – Capacitor voltage transformer with a single secondary 23

Figure 503 – Capacitor voltage transformer with two secondaries 23

Figure 504 – Capacitor voltage transformer with two tapped secondaries 23

Figure 505– Capacitor voltage transformer with one residual voltage winding and a

single secondary 23

Figure 506 – Example of a typical rating plate 26

Figure 507 – Transient response of a capacitor voltage transformer 28

Figure 508 – Flow charts test sequence to be applied when performing type test

(Figure 508a) and routine test (Figure 508b) 32

Figure 509 – Diagram of a capacitor voltage transformer for the transient response test

using equivalent circuit method 40

Figure 510 – Series burden 41

Figure 511 – Pure resistance 41

Figure 512 – Example of an error diagramme of class 1 CVT  for accuracy check with

the equivalent circuit 45

Figure 5A.1 – Example of a diagram for a capacitor voltage transformer 49

Figure 5A.2 – Example of a diagram for a capacitor voltage transformer with carrier-

frequency accessories 49

Table 501 – Limits of voltage error and phase displacement for measuring capacitor

voltage transformers 19

Table 502 – Limits of voltage error and phase displacement  for protective capacitor voltage transformers 20

Table 503 – Rated secondary voltages for capacitor voltage transformers to produce a residual voltage 21

Table 504 – Standard values of rated voltage factors for accuracy and thermal requirements 21

Table 505 – Marking of the rating plate 23

Table 506a – Ferro-resonance requirements 27

Table 506b – Ferro-resonance requirements 28

Table 507 – Standard transient response values and classes 29

Table 10 – List of tests 31

Table 508 – Test voltage for temperature rise test 34

Table 509– Burden ranges for accuracy tests 36

Table 510 – Test voltages for units, stacks and complete capacitor voltage divider 43

Table 511 – Accuracy check points (example) 45

Table 512 – Ferro resonance check 46

INSTRUMENT TRANSFORMERS –

Part 5: Additional requirements for capacitor voltage transformers

1 Scope

This part of IEC 61869 applies to new single-phase capacitor voltage transformers connected between line and ground for system voltages Um  72,5 kV at power frequencies from 15 Hz to 100 Hz. They are intended to supply a low voltage for measurement, control and protective

functions.

The capacitor voltage transformer can be equipped with or without carrier-frequency accessories for power line carrier-frequency (PLC) application at carrier frequencies from 30 kHz to 500 kHz.

The base requirements for coupling capacitors and capacitors dividers are  defined in IEC 60358. The transmission requirements for coupling devices for power line carrier (PLC) system are defined in IEC 60481.

The measurement application includes both indication measuring and revenue measuring.

2 Normative references

Clause 2 of IEC 61869-1:2007 is applicable with the following additions:

IEC 61869-1:2007, Instrument transformers – Part 1: General requirements

IEC 60038 ed7.0 (2009-06) – IEC standard voltages

IEC 60060-1, High-voltage test techniques – Part 1: General definitions and test requirements

IEC 60050-436, International Electrotechnical Vocabulary (IEV) – Chapter 436: Power capacitors

IEC 60050-601, International Electrotechnical Vocabulary (IEV) – Chapter 601: Generation, transmission and distribution of electricity – General

IEC 60050-604, International Electrotechnical Vocabulary (IEV) – Chapter 604: Generation, transmission and distribution of electricity – Operation

IEC 60358, Coupling capacitors and capacitor dividers

IEC 60481, Coupling devices for power line carrier systems

Index of abbreviations

Subclause 3.7 of IEC 61869-1 is replaced by the following: