IEC TS 62786:2017
(Main)Distributed energy resources connection with the grid
Distributed energy resources connection with the grid
IEC TS 62786:2017(E) provides principles and technical requirements for distributed energy resources (DERs) connected to the distribution network. It applies to the planning, design, operation and connection of DERs to distribution networks. It includes general requirements, connection scheme, choice of switchgear, normal operating range, immunity to disturbances, active power response to frequency deviation, reactive power response to voltage variations and voltage changes, EMC and power quality, interface protection, connection and start to generate electrical power, active power management, monitoring, control and communication, and conformance tests.
This document specifies interface requirements for connection of generating plants with the distribution network operating at a nominal frequency of 50 Hz or 60 Hz.
DERs include distributed generation and permanently connected electrical energy storage in the form of synchronous generators, asynchronous generators, converters, etc., connected to the medium voltage (MV) or low voltage (LV) distribution network.
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IEC TS 62786 ®
Edition 1.0 2017-04
TECHNICAL
SPECIFICATION
Distributed energy resources connection with the grid
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IEC TS 62786 ®
Edition 1.0 2017-04
TECHNICAL
SPECIFICATION
Distributed energy resources connection with the grid
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.240.01 ISBN 978-2-8322-4218-6
– 2 – IEC TS 62786:2017 © IEC 2017
CONTENTS
FOREWORD . 4
1 Scope and object . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Requirements on generating plants . 11
4.1 General . 11
4.2 Connection scheme . 12
4.3 Choice of switchgear . 12
4.3.1 General . 12
4.3.2 Interface switch . 12
4.4 Normal operating range . 12
4.4.1 General . 12
4.4.2 Operating frequency range . 12
4.4.3 Operating voltage range . 13
4.5 Immunity to disturbances . 13
4.5.1 General . 13
4.5.2 Rate of change of frequency (ROCOF) immunity . 13
4.5.3 Under voltage ride through (UVRT) requirements . 13
4.5.4 Over voltage ride through (OVRT) requirements . 14
4.6 Active power response to frequency deviation . 14
4.7 Reactive power response to voltage variations and voltage changes . 15
4.7.1 General . 15
4.7.2 Reactive power control . 15
4.7.3 Dynamic reactive power support capabilities . 15
4.8 EMC and power quality . 15
4.8.1 General . 15
4.8.2 Direct current (DC) injection . 16
4.9 Interface protection . 16
4.10 Connection and start to generate electrical power . 17
4.10.1 General . 17
4.10.2 Connection of synchronous generators . 17
4.10.3 Auto reclose of distribution lines . 17
4.11 Active power management . 18
4.12 Monitoring, control and communication . 18
4.12.1 Monitoring and control . 18
4.12.2 Communication . 18
5 Conformance tests . 18
Annex A (normative) Operating frequency range . 19
Annex B (normative) Operating voltage range . 20
Annex C (normative) Under voltage ride through capability of DERs . 21
Annex D (normative) Over voltage ride through parameters . 22
Bibliography . 23
Figure 1 – Electricity generating plant connected to a distribution network (schematic
view of switches) . 10
Figure 2 – Under voltage ride through capability requirements of DER . 14
Table 1 – Operating frequency requirements of DERs . 13
Table 2 – Operating voltage requirements of DERs . 13
Table 3 – Interface protection functions . 17
Table A.1 – Continuous operating frequency range . 19
Table A.2 – Limited operating frequency range . 19
Table B.1 – Continuous operating voltage range . 20
Table B.2 – Limited operating voltage range . 20
Table C.1 – UVRT capability of DERs with an interface to the grid based on a
synchronous generator . 21
Table C.2 – UVRT capability of DERs with an interface to the grid based on non-
synchronous generators (eg. converters, DFIG, etc.) . 21
Table D.1 – Medium voltage OVRT requirements . 22
– 4 – IEC TS 62786:2017 © IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DISTRIBUTED ENERGY RESOURCES
CONNECTION WITH THE GRID
FOREWORD
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IEC TS 62786 has been prepared by IEC Technical Committee 8: System aspects for
electrical energy supply.
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
8/1439/DTS 8/1457/RVDTS
Full information on the voting for the approval of this technical specification can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directive
...
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