IEC TR 62001-4:2016

IEC TR 62001-4 ®
Edition 1.0 2016-05
TECHNICAL
REPORT
High-voltage direct current (HVDC) systems – Guidance to the specification and
design evaluation of AC filters –
Part 4: Equipment
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IEC TR 62001-4 ®
Edition 1.0 2016-05
TECHNICAL
REPORT
High-voltage direct current (HVDC) systems – Guidance to the specification and

design evaluation of AC filters –

Part 4: Equipment
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.200 ISBN 978-2-8322-3400-6

– 2 – IEC TR 62001-4:2016 © IEC 2016
CONTENTS
FOREWORD .6
INTRODUCTION .8
1 Scope .9
2 Steady state rating .9
2.1 General .9
2.2 Calculation method .9
2.2.1 General .9
2.2.2 AC system pre-existing harmonics . 11
2.2.3 Combination of converter and pre-existing harmonics . 11
2.2.4 Equipment rating calculations . 12
2.2.5 Application of voltage ratings . 15
2.3 AC network conditions . 16
2.4 De-tuning effects . 16
2.5 Network impedance for rating calculations . 16
2.6 Outages . 17
3 Transient stresses and rating . 17
3.1 General . 17
3.2 Switching impulse studies . 18
3.2.1 Energization and switching . 18
3.2.2 Faults external to the filter . 19
3.2.3 Faults internal to the filter . 21
3.2.4 Transformer inrush currents . 21
3.3 Fast fronted waveform studies . 21
3.3.1 General . 21
3.3.2 Lightning strikes . 21
3.3.3 Busbar flashover studies . 22
3.4 Insulation co-ordination . 22
4 Losses . 23
4.1 Background . 23
4.2 AC filter component losses . 24
4.2.1 General . 24
4.2.2 Filter/shunt capacitor losses . 24
4.3 Reactor and resistor losses . 25
4.3.1 General . 25
4.3.2 Filter resistor losses . 26
4.3.3 Shunt reactor losses . 26
4.4 Criteria for loss evaluation . 27
4.4.1 General . 27
4.4.2 Fundamental frequency AC filter busbar voltage . 27
4.4.3 Fundamental frequency and ambient temperature . 27
4.4.4 AC system harmonic impedance . 28
4.4.5 Harmonic currents generated by the converter . 28
4.4.6 Pre-existing harmonic distortion . 29
4.4.7 The anticipated load profile of the converter station . 29
5 Design issues and special applications . 29
5.1 General . 29

5.2 Performance aspects . 30
5.2.1 Low order harmonic filtering and resonance conditions with AC system . 30
5.2.2 Definition of interference factors to include harmonics up to 5 kHz . 31
5.2.3 Triple-tuned filter circuits . 31
5.2.4 Harmonic AC filters on tertiary winding of converter transformers . 32
5.3 Rating aspects . 33
5.3.1 Limiting high harmonic currents in parallel-resonant filter circuits . 33
5.3.2 Transient ratings of parallel circuits in multiple tuned filters . 33
5.3.3 Overload protection of high-pass harmonic filter resistors . 34
5.3.4 Back-to-back switching of filters or shunt capacitors . 34
5.3.5 Short time overload – reasonable specification of requirements . 34
5.3.6 Low voltage filter capacitors without fuses . 36
5.4 Filters for special purposes . 36
5.4.1 Harmonic filters for damping transient overvoltages . 36
5.4.2 Non-linear filters for low order harmonics/transient overvoltages . 36
5.4.3 Series filters for HVDC converter stations . 37
5.4.4 Re-tunable AC filters . 40
5.5 Impact of new HVDC station in vicinity of an existing station . 41
5.6 Redundancy issues and spares . 42
5.6.1 Redundancy of filters – savings in ratings and losses . 42
5.6.2 Internal filter redundancy . 43
5.6.3 Spare parts . 43
6 Protection . 44
6.1 Overview . 44
6.2 General . 44
6.3 Bank and sub-bank overall protection . 46
6.3.1 General . 46
6.3.2 Short circuit protection . 46
6.3.3 Overcurrent protection . 46
6.3.4 Thermal overload protection . 46
6.3.5 Differential protection . 47
6.3.6 Earth fault protection . 47
6.3.7 Overvoltage and undervoltage protection . 47
6.3.8 Special protection functions and harmonic measurements . 48
6.3.9 Busbar and breaker failure protection . 48
6.4 Protection of individual filter components. 48
6.4.1 Unbalance protection for filter and shunt capacitors . 48
6.4.2 Protection of low voltage tuning capacitors . 50
6.4.3 Overload protection and detection of filter detuning . 50
6.4.4 Temperature measurement for protection . 50
6.4.5 Measurement of fundamental frequency components . 50
6.4.6 Capacitor fuses . 51
6.4.7 Protection and rating of instrument transformers . 51
6.4.8 Examples of protection arrangements . 52
6.5 Personnel protection . 52
7 Audible noise . 55
7.1 General . 55
7.2 Sound active components of AC filters . 55
7.3 Sound requirements . 56

– 4 – IEC TR 62001-4:2016 © IEC 2016
7.4 Noise reduction . 57
8 Seismic requirements . 58
...