IEC 60076-6 Power transformers –Part 6 Reactors

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CONTENTS


FOREWORD 9

INTRODUCTION 11

1Scope 12

2Normative references 12

3Terms and definitions 13

3.1Types of reactor 13

3.2Other definitions 14

4Symbols and abbreviations 17

5Service conditions 18

5.1General 18

5.2Seismic conditions 18

6Design, testing, tolerances and application 18

7Shunt reactors 20

7.1General 20

7.2Design 20

7.3Terms and definitions 20

7.4Rating 21

7.4.1Rated voltage 22

7.4.2Maximum operating voltage 22

7.4.3Rated power 22

7.4.4Zero-sequence reactance of a three-phase star-connected reactor 22

7.4.5Mutual reactance of a three-phase reactor 22

7.4.6Inrush current level 22

7.4.7Linearity of the shunt reactor 22

7.5Temperature rise 22

7.6Insulation level 23

7.7Rating plates 23

7.8Tests 23

7.8.1General 23

7.8.2Routine tests 23

7.8.3Type tests 24

7.8.4Special tests 24

7.8.5Determination of reactance and linearity of reactance 24

7.8.6Measurement of loss (routine test, special test) 25

7.8.7Measurement of harmonics of the current (special test) 26

7.8.8Measurement of zero-sequence reactance on three-phase reactors

(special test) 27

7.8.9Measurement of mutual reactance on three-phase reactors (special

test) 27

7.8.10Dielectric tests 27

7.8.11Measurement of magnetic characteristic (special test) 30

7.8.12Measurement of acoustic sound level (type test, special test) 30

7.8.13Measurement of vibration (type test) 31

7.8.14Temperature rise test (type test) 32

7.9Tolerances 33

7.9.1General 33

7.9.2Tolerances on reactance at rated voltage and rated frequency 33

7.9.3Tolerances on the linearity of reactance 33

7.9.4Tolerance on loss 33

8Current-limiting reactors and neutral-earthing reactors 33

8.1General 33

8.2Design 34

8.3Terms and definitions 34

8.4Rating 36

8.4.1Rated continuous current 36

8.4.2Rated thermal short-circuit current 37

8.4.3Rated thermal short-circuit current duration 37

8.4.4Rated mechanical short-circuit current 37

8.4.5Rated short-time current 37

8.4.6Rated short-time current duration or duty-cycle 37

8.4.7Coupling factor 38

8.4.8Rated short-circuit impedance 38

8.4.9Rated short-time impedance 39

8.4.10Rated continuous impedance 39

8.5Ability to withstand rated thermal and rated mechanical short-circuit current 39

8.6Temperature rise 39

8.6.1Temperature rise at rated continuous current 39

8.6.2Temperature due to rated thermal short-circuit current and rated

short-time current loading 40

8.7Insulation level 40

8.7.1General 40

8.8Rating plates 40

8.9Tests 41

8.9.1General 41

8.9.2Routine tests 41

8.9.3Type tests 41

8.9.4Special tests 42

8.9.5Measurement of impedance at rated continuous current (routine test) 42

8.9.6Measurement of impedance at rated short-time current (routine test) 43

8.9.7Measurement of loss (routine test, special test) 43

8.9.8Separate source a.c. withstand voltage test (routine test, special

test) 44

8.9.9Winding overvoltage test for current-limiting reactors (routine test) 44

8.9.10Winding overvoltage test for neutral-earthing reactors (routine test) 45

8.9.11Temperature rise test at rated continuous current (type test) 45

8.9.12Lightning impulse test for current-limiting reactors (type test) 46

8.9.13Short-circuit current test (special test) 46

8.9.14Measurement of acoustic sound level at rated continuous current

(special test) 47

8.9.15Vibration measurement at rated continuous current (special test) 47

8.9.16Switching impulse test (special test) 48

8.9.17Double-ended lightning impulse test (special test) 48

8.9.18Measurement of coupling factor (special test) 49

8.9.19Wet winding overvoltage test (special test) 49

8.9.20Wet separate source a.c. withstand voltage test (special test) 49

8.9.21Measurement of reactance of the winding in the case of gapped-core

and magnetically-shielded air-core reactors (special test) 49

8.10Tolerances 50

8.10.1Tolerance on impedances of reactors without compensation for

mutual coupling 50

8.10.2Tolerance on impedance of reactors with compensation for mutual

coupling 50

8.10.3Tolerance on loss 50

9Filter, damping and discharge reactors associated with capacitors 50

9.1General 50

9.2Design 51

9.3Terms and definitions 51

9.4Rating 53

9.4.1Rated power frequency current 53

9.4.2Rated current spectrum 53

9.4.3Rated inrush current 54

9.4.4Rated inrush frequency 54

9.4.5Rated discharge current 54

9.4.6Rated discharge frequency 54

9.4.7Rated thermal short-circuit current 54

9.4.8Rated thermal short-circuit current duration 54

9.4.9Rated mechanical short-circuit current 55

9.4.10Rated inductance 55

9.4.11Quality factor 55

9.5Ability to withstand rated thermal and rated mechanical short-circuit current 55

9.6Ability to withstand inrush or discharge current 56

9.7Temperature rise 56

9.7.1Temperature rise at equivalent current at power frequency 56

9.7.2Temperature due to rated thermal short-circuit current loading 56

9.8Insulation level 56

9.8.1General 56

9.8.2Insulation requirements 56

9.9Rating plates 57

9.10Tests 57

9.10.1General 57

9.10.2Routine tests 58

9.10.3Type tests 58

9.10.4Special tests 58

9.10.5Measurement of inductance (routine test, type test) 58

9.10.6Measurement of loss and quality factor (routine test, type test) 59

9.10.7Winding overvoltage test (routine test) 59

9.10.8Temperature rise test at rated continuous current (type test) 60

9.10.9Lightning impulse test (type test) 60

9.10.10Short-circuit current test (special test) 60

9.10.11Measurement of acoustic sound level at rated continuous current

(special test) 61

9.10.12Separate source a.c. withstand voltage test (special test) 62

9.10.13Inrush current withstand test (special test) 62

9.10.14Discharge current test (special test) 63

9.10.15Modified short-circuit/discharge current test (special test) 63

9.10.16Mechanical resonance test (special test) 63

9.11Tolerances 63

9.11.1Tolerance on rated inductance 63

9.11.2Tolerance on measured loss and quality factor 63

10Earthing transformers (neutral couplers) 63

10.1General 63

10.2Design 64

10.3Terms and definitions 64

10.4Rating 66

10.4.1Rated voltage 66

10.4.2Maximum operating voltage 66

10.4.3Rated zero-sequence impedance 66

10.4.4Rated continuous neutral current 66

10.4.5Rated short-time neutral current 67

10.4.6Rated short-time neutral current duration 67

10.4.7Rated voltage of the secondary winding 67

10.4.8Further ratings for the combination of an earthing transformer and an

arc-suppression reactor 67

10.5Ability to withstand the rated short-time neutral current 67

10.6Temperature rise 68

10.6.1Temperature rise at rated voltage, rated continuous neutral current

and rated power of the secondary winding 68

10.6.2Temperature after rated short-time neutral current loading 68

10.7Insulation level 68

10.8Rating plates 68

10.9Tests 69

10.9.1General 69

10.9.2Routine tests 69

10.9.3Type tests 70

10.9.4Special tests 70

10.9.5Measurement of zero-sequence impedance (routine test) 70

10.9.6Temperature rise test (type test) 71

10.9.7Dielectric tests (routine test, type test) 72

10.9.8Demonstration of ability to withstand rated short-time neutral

current (special test) 72

10.9.9Measurement of loss at rated continuous neutral current (special

test) 73

10.9.10Measurement of neutral current with three-phase excitation under

single-phase fault condition (type test) 73

10.10Tolerances 73

11Arc-suppression  reactors 74

11.1General 74

11.2Design 74

11.3Terms and definitions 74

11.4Rating 75

11.4.1Rated voltage 75

11.4.2Maximum continuous voltage 75

11.4.3Rated current 75

11.4.4Rated current duration 76

11.4.5Adjustment range 76

11.4.6Auxiliary winding 76

11.4.7Secondary winding 76

11.4.8Linearity of the arc-suppression reactor 76

11.5Temperature rise 76

11.6Insulation level 77

11.7Rating plates 77

11.8Tests 77

11.8.1General 77

11.8.2Routine tests 78

11.8.3Type tests 78

11.8.4Special tests 78

11.8.5Measurement of current at rated voltage (type test), measurement

of current (routine test) 78

11.8.6Measurement of no-load voltage of the auxiliary and secondary

windings (routine test) 78

11.8.7Temperature rise test (type test) 79

11.8.8Dielectric tests (routine test, type test) 79

11.8.9Measurement of loss (special test) 79

11.8.10Measurement of linearity (special test) 80

11.8.11Measurement of acoustic sound level (special test) 80

11.8.12Endurance tests of the inductance regulation mechanism (special

test) 80

11.8.13Demonstration of ability to withstand the dynamic effects of the

rated current (special test) 80

11.9Tolerances 81

12Smoothing reactors 81

12.1General 81

12.2Design 81

12.3Terms and definitions 81

12.4Rating 82

12.4.1Rated voltage 82

12.4.2Maximum operating voltage 82

12.4.3Rated continuous direct current 83

12.4.4Rated continuous current spectrum 83

12.4.5Short-time overload current, current spectrum and current duration or

duty-cycle 83

12.4.6Rated transient fault current 83

12.4.7Rated incremental inductance 83

12.4.8Linearity of the smoothing reactor 83

12.4.9Additional requirements for reactors with directly liquid cooled

windings 83

12.5Temperature rise 84

12.6Insulation levels 84

12.6.1Lightning impulse levels 84

12.6.2Switching impulse levels 84

12.6.3Separate source d.c. withstand voltage level 84

12.6.4Polarity-reversal withstand voltage level 84

12.6.5Separate source a.c. withstand voltage level 84

12.7Rating plates 85

12.8Tests 85

12.8.1General 85

12.8.2Routine tests 85

12.8.3Type test 86

12.8.4Special tests 86

12.8.5Measurement of incremental inductance (routine test) 86

12.8.6Measurement of the harmonic current loss and calculation of the

total loss (routine test) 87

12.8.7Separate source a.c. withstand voltage test (routine test) 88

12.8.8Separate source d.c. withstand voltage test for liquid-immersed

reactors (routine test) 88

12.8.9Polarity-reversal withstand test for liquid-immersed reactors

(routine test) 89

12.8.10Lightning impulse test (routine test) 90

12.8.11Switching impulse test (routine test, type test) 90

12.8.12Wet separate source d.c. withstand voltage test for dry-type

reactors (type test) 90

12.8.13Temperature rise test (type test) 90

12.8.14Measurement of acoustic sound level (special test) 91

12.8.15Measurement of high frequency impedance (special test) 92

12.8.16Test of the tightness of the liquid cooling circuit for reactors with directly liquid cooled windings (routine test) 92

12.8.17Measurement of the pressure drop for reactors with directly liquid cooled windings (type test) 93

12.8.18Transient fault current test (special test) 93

12.8.19Chopped wave impulse test for liquid-immersed reactors (special test) 94

12.9Tolerances 94

Annex A (informative)  Information on shunt reactor switching and on special

applications 95

Annex B (informative)  Magnetic characteristic of reactors 98

Annex C (informative)  Mutual reactance, coupling factor and equivalent reactances  of

three-phase reactors 105

Annex D (informative)  Temperature correction of losses for liquid-immersed gapped-

core and magnetically-shielded air-core reactors 108

Annex E (normative)  Turn-to-turn overvoltage test for dry-type reactors 110

Annex F (informative)  Short-circuit testing 112

Annex G (informative)  Resistors – Characteristics, specification and tests 114

Bibliography 117

Figure 1 – Types of magnetic characteristics for reactors 15

Figure 2 – Parameters for non-linear magnetic characteristic 16

Figure 3 – Measurement of mutual reactance for three-phase reactors  or banks of

three single-phase reactors 27

Figure 4 – Phase-to-earth test circuit for single-phase excitation 29

Figure 5 – Phase-to-phase test circuit for single-phase excitation 29

Figure 6 – Single-phase excitation circuit for reactors  with magnetic shield for zero-sequence flux 29

Measurement of mutual reactance for three-phase  reactors or banks of three single-phase reactors 49

Figure 8 – Single-phase fault test circuit with earthed neutral 73

Figure 9 – Single-phase fault test circuit  with earthed voltage-supply 73

Figure 10 – Measuring circuit for determining incremental  inductance of two identical smoothing reactors 87

Figure 11 – Double reversal test voltage profile 89

Figure B.1 – Illustration of linked flux and current waveshapes with a sinusoidal voltage applied to a reactor with a non-linear magnetic characteristic according to

Figure B.6 99

Figure B.2 – Circuit for measurement the magnetic characteristic according to B.7.1 102

Figure B.3 – Equivalent circuit with the reactor short-circuited 102

Figure B.4 – Measured curves of a reactors d.c. charge and discharge current 103

Figure B.5 – Calculated linked flux during discharge period (see equations B7 and B9) 104

Figure B.6 – Magnetic characteristic 104

Figure C.1 – Equivalent scheme of a three-phase reactor  including the magnetic

coupling between phases 105

Figure E.1 – Test circuit for turn-to-turn overvoltage test and sample oscillograms 111

Table 1 – Temperature limits for winding terminals of dry-type reactors 19

Table 2 – Tolerances 74

Table 3 – Tolerances 81

Table C.1 – Reactance and flux ratios for reactors with uniform magnetic coupling 106

Table C.2 – Coupling values for reactors with non-uniform magnetic coupling 107


POWER TRANSFORMERS –


Part 6: Reactors


1 Scope


This part of IEC 60076 applies to the following types of reactors:


smoothing reactors for HVDC and industrial application; with the exception of the following reactors:


Where IEC standards do not exist for small or special reactors, this part of IEC 60076 may be applicable as a whole or in part.


2 Normative references


The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.


IEC 60060-1:1989, High-Voltage test techniques – Part 1: General definitions and test requirements


IEC 60076-1:1993, Power transformers – Part 1: General

Amendment 1 (1999)


IEC 60076-2:1997, Power transformers – Part 2: Temperature rise


IEC 60076-3:2000, Power transformers – Part 3: Insulation levels, dielectric tests and external clearances in air


IEC 60076-4:2002, Power transformers – Part 4: Guide to lightning impulse and switching impulse testing – Power transformers and reactors


IEC 60076-5:2006, Power transformers – Part 5: Ability to withstand short-circuit


IEC 60076-7:2005, Power transformers – Part 7: Loading guide for oil-immersed power transformers


IEC 60076-8:1997, Power transformers – Part 8: Application guide


IEC 60076-10:2005, Power transformers – Part 10: Determination of sound levels


IEC 60076-11:2004, Power transformers – Part 11: Dry-type transformers


IEC 60137, Insulated bushings for alternating voltages above 1 000 V


IEC 60270, High-voltage test techniques – Partial discharge measurements


IEC 60721-2-6, Classification of environmental conditions – Part 2: Environmental conditions appearing in nature. Earthquake vibration and shock


IEC 60815, Guide for the selection of insulators in respect of polluted conditions


IEC 60905:1987, Loading guide for dry-type power transformers


IEC 60943:1998, Guidance concerning the permissible temperature rise for parts of electrical equipment, in particular for terminals


Bibliography


IEC 60143, Series capacitors for power systems


IEC 60168:2001, Tests on indoor and outdoor post insulators of ceramic material or glass for systems with nominal voltages greater than 1 000 V


IEC 60273:1990, Characteristic of indoor and outdoor post insulators for systems with nominal voltages greater than 1 000 V


IEC 60353, Line traps for a.c. power systems


IEC 60529, Degrees of protection provided by enclosures (IP Code)


IEC 60871-1:2005, Shunt capacitors for a.c. power systems having a rated voltage above 1000V – Part 1: General


IEC 61378-1:1997, Converter transformers – Part 1: Transformers for industrial applications


IEC 61378-2:2001, Converter transformers – Part 2: Transformers for HVDC applications


IEC 62271-110, High-voltage switchgear and controlgear – Part 110: Inductive load switching


IEEE  C57.21-1990,  IEEE  standard  requirements,  terminology,  and  test  code  for  shunt reactors rated over 500 kVA


IEEE 1277-2000, IEEE trial-use standard general requirements and test code for dry-type and oil-immersed smoothing reactors for DC power transmission


E.W. Kimbark, Suppression of Ground Fault Arcs on Single-Pole-switched EHV Lines by Shunt Reactors, IEEE Transmission and Distribution, March 1964.


Controlled switching of HVAC circuit-breakers. Guide for application lines – reactors – capacitors – transformers. 2nd Part. ELEKTRA No. 185, 1999


Interruption of small inductive currents. Chapter 6: Switching of reactor-loaded transformers. ELEKTRA No. 138, 1991