1、BSI Standards Publication Photovoltaic (PV) modules Test methods for the detection of potential-induced degradation Part 1: Crystalline silicon PD IEC/TS 62804-1:2015National foreword This Published Document is the UK implementation of IEC/TS 62804-1:2015. The UK participation in its preparation was
2、 entrusted to Technical Committee GEL/82, Photovoltaic Energy Systems. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct app
3、lication. The British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 91563 5 ICS 27.160 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was published under the authority of the Standards Policy and Strategy
4、 Committee on 30 September 2015. Amendments/corrigenda issued since publication Date Text affected PUBLISHED DOCUMENT PD IEC/TS 62804-1:2015 IEC TS 62804-1 Edition 1.0 2015-08 TECHNICAL SPECIFICATION Photovoltaic (PV) modules Test methods for the detection of potential-induced degradation Part 1: Cr
5、ystalline silicon INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 27.160 ISBN 978-2-8322-2835-7 Registered trademark of the International Electrotechnical Commission Warning! Make sure that you obtained this publication from an authorized distributor. colour inside PD IEC/TS 62804-1:2015 2 IEC TS 6280
6、4-1:2015 IEC 2015 CONTENTS FOREWORD . 3 INTRODUCTION . 5 1 Scope 6 2 Normative references 6 3 Samples 7 4 Test procedures 8 4.1 General . 8 4.2 Pre-stress tests . 9 4.3 Voltage stress test procedures 9 4.3.1 Apparatus 9 4.3.2 Stress method a), testing in damp heat using an environmental chamber 10 4
7、.3.3 Stress method b), contacting the surfaces with a conductive electrode 12 4.4 Post-stress tests . 13 5 Test report . 14 Figure 1 PID test flow 8 Figure 2 Example test time-temperature-humidity-voltage profile for application of stress in an environmental chamber 12 Figure 3 Test time-temperature
8、-voltage profile for stress method performed in 25 C ambient. 13 PD IEC/TS 62804-1:2015IEC TS 62804-1:2015 IEC 2015 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ PHOTOVOLTAIC (PV) MODULES TEST METHODS FOR THE DETECTION OF POTENTIAL-INDUCED DEGRADATION Part 1: Crystalline silicon FOREWORD 1) The Inte
9、rnational Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and elec
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17、ncluding individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or r
18、eliance upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of th
19、e 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. The main task of IEC technical committees is to prepare International Standards. In exceptional circumstances, a technical committee may propose th
20、e publication of a technical specification when the required support cannot be obtained for the publication of an International Standard, despite repeated efforts, or the subject is still under technical development or where, for any other reason, there is the future but no immediate possibility of
21、an agreement on an International Standard. Technical specifications are subject to review within three years of publication to decide whether they can be transformed into International Standards. IEC TS 62804-1, which is a technical specification, has been prepared by IEC technical committee 82: Sol
22、ar photovoltaic energy systems. PD IEC/TS 62804-1:2015 4 IEC TS 62804-1:2015 IEC 2015 The text of this standard is based on the following documents: DTS Report on voting 82/885/DTS 82/921A/RVC Full information on the voting for the approval of this standard can be found in the report on voting indic
23、ated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. A list of all parts in the IEC 62804 series, published under the general title Photovoltaic (PV) modules Test methods for the detection of potential-induced degradation, can be found on the
24、IEC website. The committee has decided that the contents of this publication will remain unchanged until the stability date indicated on the IEC website under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication will be reconfirmed, withdrawn, replac
25、ed by a revised edition, or amended. A bilingual version of this publication may be issued at a later date. IMPORTANT The colour inside logo on the cover page of this publication indicates that it contains colours which are considered to be useful for the correct understanding of its contents. Users
26、 should therefore print this document using a colour printer. PD IEC/TS 62804-1:2015IEC TS 62804-1:2015 IEC 2015 5 INTRODUCTION This part of IEC 62804 is for testing and evaluating the durability of crystalline silicon photovoltaic modules to stresses that induce potential-induced degradation (PID).
27、 The applied stresses, mainly system voltage, manifest themselves in different degradation mechanisms depending on the module technology. A series of Technical Specifications is therefore proposed to define PID tests for different photovoltaic module technologies. IEC TS 62804-1 defines test methods
28、 for evaluating PID in crystalline silicon PV modules. IEC TS 62804-2 defines test methods for evaluating PID in thin-film PV modules. Additional Technical Specifications in the series may be introduced in the future for emerging module technologies. Voltage potential that exists between the active
29、circuit and the grounded module surfaces can lead to module degradation by multiple mechanisms including ionic transport in the encapsulant, superstrate or substrate; hot carriers in the cell; redistribution of charges that degrade the active layer of the cell or its surfaces; failure of adhesion at
30、 interfaces, and corrosion of module components. These degradation mechanisms in crystalline silicon photovoltaic modules caused by voltage stress and promoted by high temperature and humidity have been labeled potential-induced degradation, polarization, electrolytic corrosion, and electrochemical
31、corrosion. They are most active in wet or damp environments, and in environments prone to soiling of modules with conductive, acidic, caustic, or ionic species that lead to increased conduction on the module surfaces. In the field, modules have been observed to degrade in positive as well as negativ
32、e polarity strings depending on the cell construction, module materials, and design. The testing in this Technical Specification therefore specifies the evaluation of the effects of voltage stress in both polarities for modules that may be operated in either polarity, or in the polarity defined by t
33、he manufacturers documented specifications. Some crystalline silicon module designs undergoing system voltage bias stress have shown degradation manifested by junction failure, leading to changes in the reverse-bias breakdown characteristics and a resulting degradation in safety because of the incre
34、ased potential for development of hot spots in the module. This Technical Specification describes two methods to measure the ability of a module to withstand degradation from system voltage effects that manifest in the relatively short term. The stress-test levels in this Technical Specification hav
35、e not been related to those of the natural environment. Modules types undergoing damp heat chamber testing with a 60 C and 85 % relative humidity stress level with the temperature, humidity, and bias voltage ramped simultaneously at the start of a 96 h stress test were found resistant to PID in outd
36、oor tests in Florida, USA. However, to improve reproducibility, test details including environmental chamber temperature and humidity ramps and tolerances have been tightened, which very significantly reduce the total stress applied and invalidate the correspondences previously found. The relevance
37、to real outdoor stress conditions of the test contained herein using foil as the ground conductor is also not proven. Alternative levels beyond the basic stress levels in this Technical Specification are thus included. It is known that variability in manufacturing processes can affect the susceptibi
38、lity of modules to system voltage stress. Retesting of module samples by the test protocols contained herein and according to sampling plans of IEC 60410, internal quality assurance programs, or external audits will aid in verifying not only the durability of the design of the module to system volta
39、ge stress, but also the effects of variability of the materials and manufacturing processes. PD IEC/TS 62804-1:2015 6 IEC TS 62804-1:2015 IEC 2015 PHOTOVOLTAIC (PV) MODULES TEST METHODS FOR THE DETECTION OF POTENTIAL-INDUCED DEGRADATION Part 1: Crystalline silicon 1 Scope This part of IEC 62804 defi
40、nes procedures to test and evaluate the durability of crystalline silicon photovoltaic (PV) modules to the effects of short-term high-voltage stress including potential-induced degradation (PID). Two test methods are defined that do not inherently produce equivalent results. They are given as screen
41、ing testsneither test includes all the factors existing in the natural environment that can affect the PID rate. The methods describe how to achieve a constant stress level. The testing in this Technical Specification is designed for crystalline silicon PV modules with one or two glass surfaces, sil
42、icon cells having passivating dielectric layers, for degradation mechanisms involving mobile ions influencing the electric field over the silicon semiconductor, or electronically interacting with the silicon semiconductor itself. This Technical Specification is not intended for evaluating modules wi
43、th thin-film technologies, tandem, or heterostructure devices. This Technical Specification describes methods to measure the module designs ability to withstand degradation from system voltage effects that manifest in the relatively short term. The testing in this Technical Specification does not pu
44、rport to examine certain combined effects that may occur over longer periods of time in modules such as encapsulation failure, which could lead in turn to rapid moisture ingress and electrochemical corrosion. This Technical Specification does not incorporate illumination of the module that can affec
45、t the rate of degradation. The test methods are designed to measure PID sensitivity and will give results according to the stress levels and the module grounding configuration inherent to the respective tests. Because stress method (a), testing in an environmental chamber, employs a non-condensing h
46、umidity level to serve as a conductive pathway to electrical ground, it frequently applies less stress toward the centre of the module face and the PID effect is concentrated toward the module edges as a result. Stress method (b), contacting the surfaces with a grounded conductive electrode, evaluat
47、es cell sensitivity and some effects of the component packaging materials such as glass and encapsulant resistivity, but does not differentiate the effects of some construction methods of mitigating PID, for example, the use of rear rail mounts, edge clips, and insulating frames. The actual durabili
48、ty of modules to system voltage stress will depend on the environmental conditions under which they are operated. These tests are intended to assess PV module sensitivity to PID irrespective of actual stresses under operation in different climates and systems. 2 Normative references The following do
49、cuments, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. PD IEC/TS 62804-1:2015IEC TS 62804-1:2015 IEC 2015 7 IEC 60068-2-78:2012, Environmental testing Part 2-78: Tests Test Cab: Damp heat, steady state IEC 60410, Sampling plans and procedures for inspection by attributes
