IEC TR 63401-4:2022

Dynamic characteristics of inverter-based resources in bulk power systems - Part 4: Behaviour of inverter-based resources in response to bulk grid faults

IEC TR 63401-4:2022 (E), which is a technical report, focuses on the fault behaviour of IBRs and performances of the existing relay protection in grids with large-scale integration of IBRs.
This document includes:
The IBR fault current requirements in present grid codes, including the requirements of active and reactive currents in positive- and negative-sequence systems during symmetrical and unsymmetrical faults.
Fault current behaviour of IBRs, including the current components in transient and fundamental frequency in different IBR topology and control schemes.
Adaptability of existing relay protection with the large-scale integration of IBRs, including the performances of distance protection, phase selector, directional relay and over-current protection.

General Information

• Status: Published
• Publication Date: 26-Jun-2022
• ICS: 29.020 - Electrical engineering in general
• Technical Committee: SC 8A - Grid Integration of Renewable Energy Generation
• Drafting Committee: JWG 5 - TC 8/SC 8A/JWG 5
• Current Stage: PPUB - Publication issued
• Start Date: 22-Jul-2022
• Completion Date: 27-Jun-2022

Standards Content (Sample)

IEC TR 63401-4 ®
Edition 1.0 2022-06
TECHNICAL
REPORT
colour
inside
Dynamic characteristics of inverter-based resources in bulk power systems –
Part 4: Behaviour of inverter-based resources in response to bulk grid faults
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IEC TR 63401-4 ®
Edition 1.0 2022-06
TECHNICAL
REPORT
colour
inside
Dynamic characteristics of inverter-based resources in bulk power systems –

Part 4: Behaviour of inverter-based resources in response to bulk grid faults

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.020 ISBN 978-2-8322-3930-8

– 2 – IEC TR 63401-4:2022  IEC 2022
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms, definitions and abbreviated terms . 8
3.1 Terms and definitions . 8
3.2 Abbreviated terms . 9
4 Existing requirements for fault current behaviour of IBRs . 9
4.1 Review of the present requirements . 9
4.2 Requirements for wind power stations and PV stations by NERC . 12
4.3 Requirements for wind power stations and PV power stations in China . 14
4.4 Requirements for wind power stations and PV power stations in Germany . 17
4.5 Clause summary . 19
5 Analysis on the behaviour of fault current . 19
5.1 Fault current needs . 19
5.2 Fault current characteristics of full-scale-converter based IBRs . 19
5.2.1 General . 19
5.2.2 Typical control schemes of FSC-based IBRs . 20
5.2.3 Fault current characteristics of FSC-based IBR during symmetrical fault. 22
5.2.4 Fault current characteristics of FSC-based IBR under unsymmetrical
fault . 22
5.3 Fault current behaviour of doubly fed induction generator (DFIG) based wind
turbine (WT) . 23
5.3.1 General . 23
5.3.2 FRT solutions of DFIG-based WT . 23
5.3.3 Fault current behaviour of DFIG-based WT during symmetrical faults . 26
5.3.4 Fault current behaviour of DFIG-based WT during unsymmetrical faults . 27
5.4 Behaviour of large-scale wind farm when outgoing line faults . 27
5.5 Clause summary . 32
6 Impact of IBRs on relay protection . 33
6.1 Influence factors of IBRs on relay protection . 33
6.2 Impact on distance protection . 34
6.2.1 Basic principle of distance protection . 34
6.2.2 Power frequency component distance relay . 36
6.2.3 Time-domain distance relay . 36
6.2.4 Power frequency variation component distance relay . 36
6.2.5 Phase-comparison distance relay . 37
6.2.6 Conclusion . 39
6.3 Impact on phase selector . 39
6.3.1 Fault component of phase current difference based phase selector . 39
6.3.2 Fault component of sequence current based phase selector . 41
6.3.3 Conclusion . 42
6.4 Impact on directional relay . 42
6.4.1 Fault component of phase voltage and current based directional relay . 42
6.4.2 Fault component of sequence voltage and current based directional
relay . 42
6.4.3 Conclusion . 44

6.5 Clause summary . 45
7 Conclusions and future work . 45
7.1 Conclusions . 45
7.2 Future work . 45
Annex A (informative) Expressions of DFIG-based WT's fault current . 46
Bibliography . 48

Figure 1 – Fault-ride-through profile of power-generating modules . 10
Figure 2 – Category Ⅰ Abnormal voltage ride-through requirement [2] . 12
Figure 3 – Category Ⅱ Abnormal voltage ride-through requirement [2] . 13
Figure 4 – Category Ⅲ Abnormal voltage ride-through requirement as amended in [2] . 13
Figure 5 – Under voltage ride through requirements for wind farms in China . 14
Figure 6 – Under voltage ride through requirements for photovoltaic power stations in
China . 15
Figure 7 – Over voltage ride through requirements for photovoltaic power stations in
China . 16
Figure 8 – Voltage ride through requirements for type II power stations according to
VDE-AR-N-4120 . 17
Figure 9 – Requirements of the reactive current according to VDE-AR-N 4120 . 18
Figure 10 – Typical topology of a Type-IV WT . 20
Figure 11 – Typical topology of a VSC-based PV inverter . 20
Figure 12 – Diagram of basic AC current control strategy of GSC during fault . 20
Figure 13 – Diagram of positive- and negative-sequence AC current control strategy of
GSC for eliminating oscillations during voltage unbalance . 21
Figure 14 – Diagram of positive- and negative-sequence AC current control strategy of
GSC for complying I1R and I2R injection requirements . 22
Figure 15 – Typical topology of a DFIG-based WT . 23
Figure 16 – Energy flow and ESEs of a DFIG-based WT in normal operation . 24
Figure 17 – ESEs and vector control scheme of a DFIG-based WT in normal operation . 24
Figure 18 – FRT solutions of a DFIG-based WT during grid fault . 25
Figure 19 – FRT solutions of a DFIG-based WT during grid fault . 26
Figure 20 – The identified components of fault currents by the analytical expression . 26
Figure 21 – The topology of wind farm integrated to power grid in Shanxi Province . 28
Figure 22 – The u and i recorded when BG fault occurs at point F1 . 28
OL OL
Figure 23 – The u and i recorded when BG fault occurs at point F1 . 29
D D
Figure 24 – The EPSI, ENSI, EZSI of wind farm including both DFIG and PMSG based
WTs . 30
Figure 25 – The EPSI, ENSI, EZSI of wind farm including only DFIG based WTs . 31
Figure 26 – The u , i and i recorded when ABCG fault occurs at point F2 . 32
OL OL D
Figure 27 – General fault characteristics of wind power system . 34
Figure 28 – Diagrams of wind power integration system for distance protection . 35
Figure 29 – Wind power integration system . 37
Figure 30 – Operation performance of distance relays when the BC fault occurs at the
midpoint of DFIG wind power outgoing line . 38

– 4 – IEC TR 63401-4:2022  IEC 2022
Figure 31 – Fault component network . 39
Figure 32 – The ratio of positive and negative sequence impedance for DFIG wind farm
when an AG fault occurs . 43
Figure 33 – Fault component of phase voltage and current based directional relay . 43
Figure 34 – Fault component of line to line voltage and current based directional relay. 44
Figure 35 – Fault component of sequence voltage and current based directional relay . 44

Table 1 – Parameters for Figure 1 for fault-ride-through capability of power-generating
modules . 10
Table 2 – Detailed parameters for Figure 1 for fault-ride-through capability of power-
generating modules in different countries . 11
Table 3 – Simulation results of distance relays when BC faults occur at different
locations of the DFIG wind power outgoing line . 39
Table 4 – Behaviour of traditional phase selectors under different kinds of faults . 41
...