IEC TR 62271-306:2012

High-voltage switchgear and controlgear - Part 306: Guide to IEC 62271-100, IEC 62271-1 and other IEC standards related to alternating current circuit-breakers

IEC/TR 62271-306:2012(E) is applicable to a.c. circuit-breakers designed for indoor or outdoor installation and for operation at frequencies of 50 Hz and 60 Hz on systems having voltages above 1 000 V. This technical report addresses utility, consultant and industrial engineers who specify and apply high-voltage circuit-breakers, circuit-breaker development engineers, engineers in testing stations, and engineers who participate in standardization. It is intended to provide background information concerning the facts and figures in the standards and provide a basis for specification for high-voltage circuit-breakers. Thus, its scope will cover the explanation, interpretation and application of IEC 62271-100 and IEC 62271-1 as well as related standards and technical reports with respect to high-voltage circuit-breakers.

Standards Content (sample)

IEC/TR 62271-306
Edition 1.0 2012-12
TECHNICAL
REPORT
colour
inside
High-voltage switchgear and controlgear –
Part 306: Guide to IEC 62271-100, IEC 62271-1 and other IEC standards related to
alternating current circuit-breakers
IEC/TR 62271-306:2012(E)
---------------------- Page: 1 ----------------------
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IEC/TR 62271-306
Edition 1.0 2012-12
TECHNICAL
REPORT
colour
inside
High-voltage switchgear and controlgear –
Part 306: Guide to IEC 62271-100, IEC 62271-1 and other IEC standards related
to alternating current circuit-breakers
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Warning! Make sure that you obtained this publication from an authorized distributor.

® Registered trademark of the International Electrotechnical Commission
---------------------- Page: 3 ----------------------
– 2 – TR 62271-306 © IEC:2012(E)
CONTENTS

FOREWORD ......................................................................................................................... 15

1 General .......................................................................................................................... 17

1.1 Scope .................................................................................................................... 17

1.2 Normative references ............................................................................................ 17

2 Evolution of IEC standards for high-voltage circuit-breaker ............................................. 18

3 Classification of circuit-breakers ..................................................................................... 22

3.1 General ................................................................................................................. 22

3.2 Electrical endurance class E1 and E2 .................................................................... 22

3.3 Capacitive current switching class C1 and C2 ....................................................... 23

3.4 Mechanical endurance class M1 and M2 ............................................................... 23

3.5 Class S1 and S2 .................................................................................................... 24

3.5.1 General ..................................................................................................... 24

3.5.2 Cable system ............................................................................................. 24

3.5.3 Line system ............................................................................................... 24

3.6 Conclusion ............................................................................................................ 24

4 Insulation levels and dielectric tests ............................................................................... 25

4.1 General ................................................................................................................. 25

4.2 Longitudinal voltage stresses ................................................................................ 28

4.3 High-voltage tests ................................................................................................. 28

4.4 Impulse voltage withstand test procedures ............................................................ 29

4.4.1 General ..................................................................................................... 29

4.4.2 Application to high-voltage switching devices ............................................ 29

4.4.3 Additional criteria to pass the tests ............................................................ 30

4.4.4 Review and perspective ............................................................................. 30

4.4.5 Theory ....................................................................................................... 33

4.4.6 Summary of 15/2 and 3/9 test methods ...................................................... 36

4.4.7 Routine tests ............................................................................................. 37

4.5 Correction factors .................................................................................................. 37

4.5.1 Altitude correction factor ............................................................................ 37

4.5.2 Humidity correction factor .......................................................................... 40

4.6 Background information about insulation levels and tests ...................................... 41

4.6.1 Specification .............................................................................................. 41

4.6.2 Testing ...................................................................................................... 43

4.6.3 Combined voltage tests of longitudinal insulation ....................................... 43

4.7 Lightning impulse withstand considerations of vacuum interrupters ....................... 44

4.7.1 General ..................................................................................................... 44

4.7.2 Conditioning during vacuum interrupter manufacturing .............................. 44

4.7.3 De-conditioning in service.......................................................................... 45

4.7.4 Re-conditioning in service.......................................................................... 45

4.7.5 Performing lightning impulse withstand voltage tests ................................. 45

5 Rated normal current and temperature rise ..................................................................... 45

5.1 General ................................................................................................................. 45

5.2 Load current carrying requirements ....................................................................... 45

5.2.1 Rated normal current ................................................................................. 45

5.2.2 Load current carrying capability under various conditions of ambient

temperature and load................................................................................. 46

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TR 62271-306 © IEC:2012(E) – 3 –

5.3 Temperature rise testing ........................................................................................ 49

5.3.1 Influence of power frequency on temperature rise and temperature

rise tests ................................................................................................... 49

5.3.2 Test procedure .......................................................................................... 49

5.3.3 Temperature rise test on vacuum circuit-breakers ...................................... 51

5.3.4 Resistance measurement .......................................................................... 52

5.4 Additional information ............................................................................................ 52

5.4.1 Table with ratios I /I ................................................................................. 52

a r

5.4.2 Derivation of temperature rise equations ................................................... 52

6 Transient recovery voltage ............................................................................................. 53

6.1 Harmonization of IEC and IEEE transient recovery voltages .................................. 53

6.1.1 General ..................................................................................................... 53

6.1.2 A summary of the TRV changes ................................................................. 54

6.1.3 Revision of TRVs for rated voltages of 100 kV and above .......................... 57

6.1.4 Revision of TRVs for rated voltages less than 100 kV ................................ 60

6.2 Initial Transient Recovery Voltage (ITRV) .............................................................. 62

6.2.1 Basis for specification ................................................................................ 62

6.2.2 Applicability ............................................................................................... 63

6.2.3 Test duties where ITRV is required ............................................................ 63

6.2.4 ITRV waveshape ....................................................................................... 64

6.2.5 Standard values of ITRV ............................................................................ 64

6.3 Testing .................................................................................................................. 65

6.3.1 ITRV measurement .................................................................................... 65

6.3.2 SLF with ITRV ........................................................................................... 66

6.3.3 Unit testing ................................................................................................ 67

7 Short-line faults .............................................................................................................. 67

7.1 Short-line fault requirements ................................................................................. 67

7.1.1 Basis for specification ................................................................................ 67

7.1.2 Technical comment .................................................................................... 68

7.1.3 Single-phase faults .................................................................................... 68

7.1.4 Surge impedance of the line ...................................................................... 68

7.1.5 Peak voltage factor .................................................................................... 69

7.1.6 Rate-of-Rise of Recovery Voltage (RRRV) factor "s" .................................. 71

7.2 SLF testing ............................................................................................................ 72

7.2.1 Test voltage ............................................................................................... 72

7.2.2 Operating sequence .................................................................................. 72

7.2.3 Test duties ................................................................................................ 72

7.2.4 Test current asymmetry ............................................................................. 73

7.2.5 Line side time delay ................................................................................... 74

7.2.6 Supply side circuit ..................................................................................... 74

7.3 Additional explanations on SLF ............................................................................. 75

7.3.1 Surge impedance evaluation ...................................................................... 75

7.3.2 Influence of additional capacitors on SLF interruption ................................ 75

7.4 Comparison of surge impedances .......................................................................... 80

7.5 Calculation of actual percentage of SLF breaking currents .................................... 81

7.6 TRV with parallel capacitance ............................................................................... 82

8 Out-of-phase switching ................................................................................................... 85

8.1 Reference system conditions ................................................................................. 85

8.1.1 General ..................................................................................................... 85

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8.1.2 Case A ...................................................................................................... 85

8.1.3 Case B ...................................................................................................... 86

8.2 TRV parameters introduced into Tables 1b and 1c of the first edition of

IEC 62271-100 ...................................................................................................... 87

8.2.1 General ..................................................................................................... 87

8.2.2 Case A ...................................................................................................... 87

8.2.3 Case B ...................................................................................................... 88

8.2.4 TRV parameters for out-of-phase testing ................................................... 88

9 Switching of capacitive currents ..................................................................................... 90

9.1 General ................................................................................................................. 90

9.2 General theory of capacitive current switching ....................................................... 90

9.2.1 De-energisation of capacitive loads ........................................................... 90

9.2.2 Energisation of capacitive loads .............................................................. 103

9.3 Non-sustained disruptive discharge (NSDD) ........................................................ 121

9.4 General application considerations ...................................................................... 124

9.4.1 General ................................................................................................... 124

9.4.2 Maximum voltage for application .............................................................. 124

9.4.3 Rated frequency ...................................................................................... 124

9.4.4 Rated capacitive current .......................................................................... 124

9.4.5 Voltage and earthing conditions of the network ........................................ 125

9.4.6 Restrike performance .............................................................................. 126

9.4.7 Class of circuit-breaker ............................................................................ 126

9.4.8 Transient overvoltages and overvoltage limitation .................................... 126

9.4.9 No-load overhead lines ............................................................................ 128

9.4.10 Capacitor banks ...................................................................................... 130

9.4.11 Switching through transformers ............................................................... 137

9.4.12 Effect of transient currents ....................................................................... 138

9.4.13 Exposure to capacitive switching duties during fault switching ................. 140

9.4.14 Effect of load ........................................................................................... 140

9.4.15 Effect of reclosing .................................................................................... 141

9.4.16 Resistor thermal limitations ..................................................................... 141

9.4.17 Application considerations for different circuit-breaker types.................... 141

9.5 Considerations of capacitive currents and recovery voltages under fault

conditions ............................................................................................................ 143

9.5.1 Voltage and current factors ...................................................................... 143

9.5.2 Reasons for these specific tests being non-mandatory in the

standard .................................................................................................. 144

9.5.3 Contribution of a capacitor bank to a fault ................................................ 144

9.5.4 Switching overhead lines under faulted conditions ................................... 145

9.5.5 Switching capacitor banks under faulted conditions ................................. 146

9.5.6 Switching cables under faulted conditions................................................ 148

9.5.7 Examples of application alternatives ........................................................ 148

9.6 Explanatory notes regarding capacitive current switching tests ............................ 149

9.6.1 General ................................................................................................... 149

9.6.2 Restrike performance .............................................................................. 149

9.6.3 Test programme ...................................................................................... 149

9.6.4 Subclause 6.111.3 of IEC 62271-100:2008 – Characteristics of

supply circuit ........................................................................................... 149

9.6.5 Subclause 6.111.5 of IEC 62271-100:2008 – Characteristics of the

capacitive circuit to be switched .............................................................. 149

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TR 62271-306 © IEC:2012(E) – 5 –

9.6.6 Subclause 6.111.9.1.1 of IEC 62271-100:2008 – Class C2 test duties ..... 149

9.6.7 Subclauses 6.111.9.1.1 and 6.111.9.2.1 of IEC 62271-100:2008 –

Class C1 and C2 test duties .................................................................... 150

9.6.8 Subclauses 6.111.9.1.2 and 6.111.9.1.3 of IEC 62271-100:2008 –
Single-phase and three-phase line- and cable-charging current

switching tests ......................................................................................... 150

9.6.9 Subclauses 6.111.9.1.2. to 6.111.9.1.5 of IEC 62271-100:2008 –
Three-phase and single-phase line, cable and capacitor bank

switching tests ......................................................................................... 150

9.6.10 Subclauses 6.111.9.1.4 and 6.111.9.1.5 of IEC 62271-100:2008 –

Three-phase and single-phase capacitor bank switching tests ................. 150

10 Gas tightness ............................................................................................................... 151

10.1 Specification........................................................................................................ 151

10.2 Testing ................................................................................................................ 151

10.3 Cumulative test method and calibration procedure for type tests on closed

pressure systems ................................................................................................ 152

10.3.1 Description of the cumulative test method................................................ 152

10.3.2 Sensitivity, accuracy and calibration ........................................................ 153

10.3.3 Test set-up and test procedure ................................................................ 153

10.3.4 Example: leakage rate measurement of a circuit-breaker during low

temperature test ...................................................................................... 154

11 Miscellaneous provisions for breaking tests .................................................................. 155

11.1 Energy for operation to be used during demonstration of the rated operating

sequence during short-circuit making and breaking tests ..................................... 155

11.2 Alternative operating mechanisms ....................................................................... 156

11.2.1 General ................................................................................................... 156

11.2.2 Comparison of the mechanical characteristics ......................................... 157

11.2.3 Comparison of T100s test results ............................................................ 159

11.2.4 Additional test T100a ............................................................................... 161

11.2.5 Conclusions ............................................................................................. 162

12 Rated and test frequency .............................................................................................. 162

12.1 General ............................................................................................................... 162

12.2 Basic considerations ........................................................................................... 163

12.2.1 Temperature rise tests ............................................................................. 163

12.2.2 Short-time withstand current and peak withstand current tests ................. 163

12.2.3 Short-circuit making current ..................................................................... 163

12.2.4 Terminal faults ......................................................................................... 163

12.2.5 Short-line fault ......................................................................................... 164

12.2.6 Capacitive current switching .................................................................... 164

12.3 Applicability of type tests at different frequencies ................................................ 164

12.3.1 Temperature rise tests ............................................................................. 164

12.3.2 Short-time withstand current and peak withstand current tests ................. 165

12.3.3 Short-circuit making current test .............................................................. 165

12.3.4 Terminal faults (direct and synthetic tests) ............................................... 165

12.3.5 Short-line fault (direct and synthetic tests) ............................................... 166

12.3.6 Capacitive current switching .................................................................... 166

13 Terminal faults.............................................................................................................. 167

13.1 General ............................................................................................................... 167

13.2 Demonstration of arcing time ............................................................................... 167

13.3 Demonstration of the arcing time for three-phase tests ........................................ 168

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13.4 Power frequency recovery voltage and the selection of the first-pole-to-clear

factors 1,0; 1,2; 1,3 and 1,5 ................................................................................. 168

13.4.1 General ................................................................................................... 168

13.4.2 Equations for the first, second and third-pole-to-clear factors .................. 169

13.4.3 Standardised values for the second- and third- pole-to-clear factors ........ 171

13.5 Characteristics of recovery voltage ...................................................................... 171

13.5.1 Values of rate-of-rise of recovery voltage and time delays ....................... 171

13.5.2 Amplitude factors ..................................................................................... 172

13.6 Arcing window and k requirements for testing .................................................... 172

13.7 Single-phase testing to cover three-phase testing requirements .......................... 176

13.8 Combination tests for k = 1,3 and 1,5............................................................... 176

13.9 Suitability of a particular short-circuit current rated circuit-breaker for use at

an application with a lower short-circuit requirement............................................ 176

13.10 Basis for the current and TRV values of the basic short-circuit test-duty T10 ....... 177

14 Double earth fault ......................................................................................................... 178

14.1 Basis for specification ......................................................................................... 178

14.2 Short-circuit current ............................................................................................. 179

14.3 TRV ..................................................................................................................... 179

14.4 Determination of the short-circuit current in the case of a double-earth fault ........ 180

15 Transport, storage, installation, operation and maintenance ......................................... 182

15.1 General ............................................................................................................... 182

15.2 Transport and storage ......................................................................................... 183

15.3 Installation........................................................................................................... 184

15.4 Commissioning .................................................................................................... 184

15.5 Operation ............................................................................................................ 186

15.6 Maintenance ........................................................................................................ 186

16 Inductive load switching ................................................................................................ 186

16.1 General ............................................................................................................... 186

16.2 Shunt reactor switching ....................................................................................... 187

16.2.1 General ................................................................................................... 187

16.2.2 Chopping overvoltages ............................................................................ 187

16.2.3 Re-ignition overvoltages .......................................................................... 194

16.2.4 Oscillation circuits ................................................................................... 195

16.2.5 Overvoltage limitation .............................................................................. 197

16.2.6 Circuit-breaker specification and selection ............................................... 198

16.2.7 Testing .................................................................................................... 200

16.3 Motor switching ................................................................................................... 200

16.3.1 General ................................................................................................... 200

16.3.2 Chopping and re-ignition overvoltages ..................................................... 201

16.3.3 Voltage escalation ................................................................................... 202

16.3.4 Virtual current chopping ........................................................................... 202

16.3.5 Overvoltage limitation .............................................................................. 203

16.3.6 Circuit-breaker specification and selection .........................
...