IEC TR 62681:2014

IEC TR 62681 ®
Edition 1.0 2014-08
TECHNICAL
REPORT
colour
inside
Electromagnetic performance of high voltage direct current (HVDC) overhead
transmission lines
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IEC TR 62681 ®
Edition 1.0 2014-08
TECHNICAL
REPORT
colour
inside
Electromagnetic performance of high voltage direct current (HVDC) overhead

transmission lines
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XD
ICS 29.240.20 ISBN 978-2-8322-1780-1

– 2 – IEC TR 62681:2014  IEC 2014
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Terms and definitions . 9
3 Electric field and ion current . 10
3.1 Description of the physical phenomena . 10
3.2 Calculation methods . 13
3.2.1 General . 13
3.2.2 Semi-analytic method . 14
3.2.3 Finite element method . 16
3.2.4 BPA method . 17
3.2.5 Empirical methods of EPRI . 18
3.2.6 Recent progress . 18
3.3 Experimental data . 19
3.3.1 General . 19
3.3.2 Instrumentation and measurement methods . 19
3.3.3 Experimental results for electric field and ion current . 21
3.3.4 Discussion . 21
3.4 Implication for human and natural environment . 22
3.4.1 General . 22
3.4.2 Static electric field . 23
3.4.3 Research on space charge . 23
3.4.4 Scientific review . 28
3.5 Design practice of different countries . 29
4 Magnetic field . 30
4.1 Description of physical phenomena . 30
4.2 Magnetic field of HVDC transmission lines . 31
5 Radio interference (radio noise) . 32
5.1 Description of radio interference phenomena of HVDC transmission system . 32
5.1.1 General . 32
5.1.2 Physical aspects of d.c. corona . 32
5.1.3 Mechanism of formation of a noise field of d.c. line . 33
5.1.4 Characteristics of radio interference from d.c. line . 33
5.1.5 Factors influencing the RI from d.c. line . 34
5.2 Calculation methods . 36
5.2.1 EPRI empirical formula . 36
5.2.2 IREQ empirical method . 37
5.2.3 CISPR bipolar line RI prediction formula . 38
5.2.4 Comparison of different prediction formula . 38
5.3 Experimental data . 38
5.3.1 Measurement apparatus and methods . 38
5.3.2 Experimental results for radio interference . 39
5.4 Criteria of different countries . 39
6 Audible noise . 40
6.1 Basic principles of audible noise . 40
6.2 Description of physical phenomena . 41

6.2.1 Lateral profiles . 42
6.2.2 Statistical distribution . 44
6.2.3 Influencing factors . 45
6.2.4 Effect of altitude above sea level . 47
6.2.5 Concluding remarks . 47
6.3 Calculation methods . 48
6.3.1 General . 48
6.3.2 Theoretical analysis of audible noise propagation . 48
6.3.3 Empirical formulas of audible noise . 49
6.3.4 Semi-empirical formulas of audible noise . 49
6.3.5 CEPRI (China) research results . 52
6.3.6 Concluding remarks . 52
6.4 Experimental data . 52
6.4.1 Measurement techniques and instrumentation . 52
6.4.2 Experimental results for audible noise . 53
6.5 Design practice of different countries . 53
6.5.1 General . 53
6.5.2 The effect of audible noise on people . 53
6.5.3 The audible noise level and induced complaints . 54
6.5.4 Limit values of audible noise of HVDC transmission lines in different
countries . 57
6.5.5 Recommended noise level limit . 58
6.5.6 Main conclusion . 58
Annex A (informative) Experimental results for electric field and ion current. 59
A.1 Bonneville Power Administration ±500 kV HVDC transmission line . 59
A.2 FURNAS ±600 kV HVDC transmission line . 59
A.3 Manitoba Hydro ±450 kV HVDC transmission line . 60
A.4 Hydro-Québec – New England ±450 kV HVDC transmission line . 62
A.5 IREQ test line study of ±450 kV HVDC line configuration . 63
A.6 HVTRC test line study of ±400 kV HVDC line configuration . 64
A.7 Test study in China . 66
Annex B (informative) Experimental results for radio interference . 68
B.1 Bonneville power administration’s 1 100 kV direct current test project . 68
B.1.1 General . 68
B.1.2 Lateral profile . 68
B.1.3 Influence of conductor gradient . 69
B.1.4 Percent cumulative distribution . 70
B.1.5 Influence of wind . 72
B.1.6 Spectrum . 72
B.2 Hydro-Québec institute of research . 74
B.2.1 General . 74
B.2.2 Cumulative distribution . 74
B.2.3 Spectrum . 75
B.2.4 Lateral profiles . 75
B.2.5 Cumulative distribution under different voltage . 76
B.3 d.c. line of China . 76
Annex C (informative) Experimental results for audible noise . 78
Bibliography . 81

– 4 – IEC TR 62681:2014  IEC 2014

Figure 1 – Unipolar and bipolar space charge regions of a HVDC transmission line [1] . 11
Figure 2 – Lateral profile of magnetic field on the ground of ±800 kV HVDC lines . 32
Figure 3 – The c
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