1、Photovoltaic (PV) arrays Design requirementsBS IEC 62548:2016BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06National forewordThis British Standard is the UK implementation of IEC 62548:2016. It supersedes PD IEC/TS 62548:2013 which is withdrawn.The UK participation
2、in its preparation was entrusted to TechnicalCommittee GEL/82, Photovoltaic Energy Systems.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions ofa contract. Users are responsible fo
3、r its correct application. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 88317 0ICS 27.160Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and
4、Strategy Committee on 31 October 2016.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS IEC 62548:2016IEC 62548 Edition 1.0 2016-09 INTERNATIONAL STANDARD NORME INTERNATIONALE Photovoltaic (PV) arrays Design requirements Groupes photovoltaques (PV) Exigences de conce
5、ption INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE ICS 27.160 ISBN 978-2-8322-3635-2 Registered trademark of the International Electrotechnical Commission Marque dpose de la Commission Electrotechnique Internationale Warning! Make sure that you obtained this p
6、ublication from an authorized distributor. Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agr. colourinsideBS IEC 62548:2016 2 IEC 62548:2016 IEC 2016 CONTENTS FOREWORD . 5 1 Scope and object . 7 2 Normative references. 7 3 Terms, definitions, symbols and
7、 abbreviated terms . 9 3.1 Terms, definitions and symbols 9 3.2 Abbreviations 16 4 Compliance with IEC 60364 (all parts) 16 5 PV array system configuration 16 5.1 General . 16 5.1.1 Functional configuration of a PV system . 16 5.1.2 PV system architectures . 17 5.1.3 Array electrical diagrams 17 5.1
8、.4 Use of PCE with multiple DC inputs 22 5.1.5 Strings constructed using DC conditioning units 23 5.1.6 Series-parallel configuration . 24 5.1.7 Batteries in systems . 25 5.1.8 Considerations due to prospective fault conditions within a PV array . 25 5.1.9 Considerations due to operating temperature
9、 25 5.1.10 Performance issues . 26 5.2 Mechanical design 26 5.2.1 General . 26 5.2.2 Thermal aspects 27 5.2.3 Mechanical loads on PV structures . 27 5.2.4 Corrosion . 27 6 Safety issues . 28 6.1 General . 28 6.1.1 Overview . 28 6.1.2 Separation of PV array from main AC power output circuits . 28 6.2
10、 Protection against electric shock . 29 6.2.1 General . 29 6.2.2 Protective measure: double or reinforced insulation 29 6.2.3 Protective measure: extra-low-voltage provided by SELV or PELV 29 6.3 Protection against thermal effects 29 6.4 Protection against the effects of insulation faults 29 6.4.1 G
11、eneral . 29 6.4.2 Detection and fault indication requirements 30 6.5 Protection against overcurrent . 34 6.5.1 General . 34 6.5.2 Requirement for overcurrent protection . 34 6.5.3 Requirement for string overcurrent protection . 34 6.5.4 Requirement for sub-array overcurrent protection . 35 6.5.5 Ove
12、rcurrent protection sizing 35 6.5.6 Overcurrent protection in PV systems connected to batteries 37 6.5.7 Overcurrent protection location . 37 6.6 Protection against effects of lightning and overvoltage . 38 6.6.1 General . 38 BS IEC 62548:2016IEC 62548:2016 IEC 2016 3 6.6.2 Protection against overvo
13、ltage . 38 7 Selection and erection of electrical equipment 39 7.1 General . 39 7.2 PV array maximum voltage 40 7.3 Component requirements 40 7.3.1 General . 40 7.3.2 PV modules . 41 7.3.3 PV array and PV string combiner boxes 41 7.3.4 Circuit breakers . 42 7.3.5 Fuses 42 7.3.6 Disconnectors and swi
14、tch-disconnectors . 42 7.3.7 Cables . 43 7.3.8 Segregation of AC and DC circuits . 46 7.3.9 Plugs, sockets and connectors . 46 7.3.10 Wiring in combiner boxes . 47 7.3.11 Bypass diodes . 47 7.3.12 Blocking diodes 47 7.3.13 Power conversion equipment (PCE) including DC conditioning units (DCUs) 47 7.
15、4 Location and installation requirements . 48 7.4.1 Disconnecting means . 48 7.4.2 Earthing and bonding arrangements . 49 7.4.3 Wiring system 54 8 Acceptance . 56 9 Operation/maintenance 56 10 Marking and documentation . 56 10.1 Equipment marking . 56 10.2 Requirements for signs 56 10.3 Identificati
16、on of a PV installation 57 10.4 Labelling of PV array and PV string combiner boxes 57 10.5 Labelling of disconnection devices . 57 10.5.1 General . 57 10.5.2 PV array disconnecting device 57 10.6 Documentation 57 Annex A (informative) Examples of signs 58 Annex B (informative) Examples of system fun
17、ctional earthing configurations in PV arrays . 59 Annex C (informative) Blocking diode . 61 C.1 Introduction . 61 C.2 Use of blocking diodes to prevent overcurrent/fault current in arrays 61 C.3 Examples of blocking diode use in fault situations 61 C.3.1 General . 61 C.3.2 Short circuit in PV string
18、 . 61 C.4 Specification of blocking diode 63 C.5 Heat dissipation design for blocking diode . 63 Annex D (informative) Arc fault detection and interruption in PV arrays . 65 Annex E (normative) DVC limits . 66 Bibliography . 67 BS IEC 62548:2016 4 IEC 62548:2016 IEC 2016 Figure 1 General functional
19、configuration of a PV powered system 17 Figure 2 PV array diagram single string example . 18 Figure 3 PV array diagram multiple parallel string example 19 Figure 4 PV array diagram multiple parallel string example with array divided into sub-arrays 20 Figure 5 PV array example using a PCE with multi
20、ple MPPT DC inputs . 21 Figure 6 PV array example using a PCE with multiple DC inputs internally connected to a common DC bus 22 Figure 7 PV string constructed using DC conditioning units . 24 Figure 8 Example of a PV array diagram where strings are grouped under one overcurrent protection device pe
21、r group 36 Figure 9 Examples of reinforced protection of wiring . 45 Figure 10 PV array exposed conductive parts functional earthing/bonding decision tree . 51 Figure 11 Exposed conductive parts earthing in a PV array . 52 Figure 12 Examples of PV string wiring with minimum loop area . 55 Figure A.1
22、 Example of sign required on PV array combiner boxes (10.4) . 58 Figure A.2 Example of switchboard sign for identification of PV on a building 58 Figure B.1 System functional earthing/grounding 59 Figure B.2 Examples different PV configurations in common use . 60 Figure C.1 Effect of blocking diode
23、where there is a short circuit in PV string 62 Figure C.2 Effect of blocking diode where there is an earth fault on a system with earthing on the minus side 62 Figure C.3 Effect of blocking diode where there is an earth fault on a system with positive side earthing 63 Figure D.1 Examples of types of
24、 arcs in PV arrays 65 Table 1 Requirements for different system types based on PCE isolation and PV array functional earthing . 31 Table 2 Minimum insulation resistance thresholds for detection of failure of insulation to earth . 32 Table 3 Rated current of automatic earth fault interrupting means .
25、 33 Table 4 Voltage correction factors for crystalline and multi-crystalline silicon PV modules . 40 Table 5 Minimum current rating of circuits 44 Table 6 Disconnection device requirements in PV array installations . 49 Table E.1 Summary of the limits of the decisive voltage classes 66 BS IEC 62548:
26、2016IEC 62548:2016 IEC 2016 5 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ PHOTOVOLTAIC (PV) ARRAYS DESIGN REQUIREMENTS FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Com
27、mittees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Avai
28、lable Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non-governmental or
29、ganizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technica
30、l matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees. 3) IEC Publications have the form of recommendations for international use and are accepted by IEC N
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33、itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies. 6) All users should ensure th
34、at they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any na
35、ture whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative references cited in this publication. Use of the referenc
36、ed publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. Internati
37、onal Standard IEC 62548 has been prepared by IEC technical committee 82: Solar photovoltaic energy systems. This International Standard cancels and replaces the first edition of IEC TS 62548 published in 2013. This International Standard includes the following significant technical changes with resp
38、ect to IEC TS 62548: a) provisions for systems including DC to DC conditioning units; b) considerable revision of Clause 6 on safety issues which includes provisions for protection against electric shock including array insulation monitoring and earth fault detection. BS IEC 62548:2016 6 IEC 62548:2
39、016 IEC 2016 The text of this document is based on the following documents: FDIS Report on voting 82/1149/FDIS 82/1166/RVD Full information on the voting for the approval of this document can be found in the report on voting indicated in the above table. This document has been drafted in accordance
40、with the ISO/IEC Directives, Part 2. Attention is drawn to the co-existence of IEC 60364-7-712 and IEC 62548. Both standards have been developed in close coordination by different technical committees. The committee has decided that the contents of this document will remain unchanged until the stabi
41、lity date indicated on the IEC website under “http:/webstore.iec.ch“ in the data related to the specific document. At this date, the document will be reconfirmed, withdrawn, replaced by a revised edition, or amended. IMPORTANT The colour inside logo on the cover page of this publication indicates th
42、at it contains colours which are considered to be useful for the correct understanding of its contents. Users should therefore print this document using a colour printer. BS IEC 62548:2016IEC 62548:2016 IEC 2016 7 PHOTOVOLTAIC (PV) ARRAYS DESIGN REQUIREMENTS 1 Scope and object This International Sta
43、ndard sets out design requirements for photovoltaic (PV) arrays including DC array wiring, electrical protection devices, switching and earthing provisions. The scope includes all parts of the PV array up to but not including energy storage devices, power conversion equipment or loads. An exception
44、is that provisions relating to power conversion equipment are covered only where DC safety issues are involved. The interconnection of small DC conditioning units intended for connection to PV modules are also included. The object of this document is to address the design safety requirements arising
45、 from the particular characteristics of photovoltaic systems. Direct current systems, and PV arrays in particular, pose some hazards in addition to those derived from conventional AC power systems, including the ability to produce and sustain electrical arcs with currents that are not greater than n
46、ormal operating currents. In grid connected systems, the safety requirements of this document are however critically dependent on the inverters associated with PV arrays complying with the requirements of IEC 62109-1 and IEC 62109-2. Installation requirements are also critically dependent on complia
47、nce with the IEC 60364 series (see Clause 4). PV arrays of less than 100 W and less than 35 V DC open circuit voltage at STC are not covered by this document. PV arrays in grid connected systems connected to medium or high voltage systems are not covered in this document. Variations and additional r
48、equirements for large-scale ground mounted PV power plants with restricted access to personnel will also be addressed in IEC TS 627381. Additional requirements may be needed for more specialized installations, for example concentrating systems, tracking systems or building integrated PV. The present
49、 international standard also includes extra protection requirements of PV arrays when they are directly connected with batteries at the DC level. 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any a
