1、Photovoltaic system performance Part 3: Energy evaluation method PD IEC/TS 61724-3:2016 BSI Standards Publication WB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06National foreword This Published Document is the UK implementation of IEC/TS 61724-3:2016. The UK participation in its preparation
2、 was 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
3、 application. The British Standards Institution 2016. Published by BSI Standards Limited 2016 ISBN 978 0 580 89970 6 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 Stra
4、tegy Committee on 31 August 2016. Amendments/corrigenda issued since publication Date Text affected PUBLISHED DOCUMENT PD IEC/TS 61724-3:2016 IEC TS 61724-3 Edition 1.0 2016-07 TECHNICAL SPECIFICATION Photovoltaic system performance Part 3: Energy evaluation method INTERNATIONAL ELECTROTECHNICAL COM
5、MISSION ICS 27.160 ISBN 978-2-8322-3531-7 Registered trademark of the International Electrotechnical Commission Warning! Make sure that you obtained this publication from an authorized distributor. colour inside PD IEC/TS 61724-3:2016 2 IEC TS 61724-3:2016 IEC 2016 CONTENTS FOREWORD . 4 INTRODUCTION
6、 . 6 1 Scope 7 2 Normative references. 8 3 Terms and definitions 8 4 Test scope, schedule and duration . 11 5 Equipment and measurements . 11 6 Procedure . 12 6.1 Overview. 12 6.2 Calculation and documentation of predicted energy and the method that will be used to calculate the expected energy 14 6
7、.2.1 General . 14 6.2.2 Definition of test boundary to align with intended system boundary . 14 6.2.3 Definition of the meteorological inputs used for the prediction . 15 6.2.4 Definition of the PV inputs used for the prediction . 15 6.2.5 Definition of measured data that will be collected during th
8、e test . 16 6.2.6 Definition of the model calculations 17 6.2.7 Predicted energy for the specified system and time period 18 6.2.8 Uncertainty definition . 18 6.3 Measurement of data. 19 6.4 Identification of data associated with unavailability . 19 6.5 Identification of erroneous data and replaceme
9、nt or adjustment of such data and preparation of model input dataset 19 6.5.1 General . 19 6.5.2 Data checks for each data stream 20 6.5.3 Shading of irradiance sensor 20 6.5.4 Calibration accuracy 21 6.5.5 Final check 21 6.5.6 Using data from multiple sensors 21 6.5.7 Substitution of back-up data f
10、or erroneous or missing data . 22 6.5.8 Out-of-range data or data that are known to be incorrect . 22 6.5.9 Missing data 22 6.5.10 Partially missing data or partial unavailability 22 6.5.11 Curtailment because of external requirement 23 6.5.12 Inverter clipping (constrained operation) . 23 6.5.13 Pl
11、anned outage or force majeure 23 6.5.14 Grid support events (e.g. deviation from unity power factor) 23 6.6 Calculation of expected energy 23 6.6.1 General . 23 6.6.2 Measure inputs 24 6.6.3 Acceptability of data . 24 6.6.4 Time interval consistency . 24 6.6.5 Time stamp alignment 24 6.6.6 Calculate
12、 expected energy during times of unavailability . 24 6.6.7 Calculate expected energy during times of availability . 24 6.6.8 Calculate total expected energy 24 6.6.9 Analyse discrepancies 24 PD IEC/TS 61724-3:2016IEC TS 61724-3:2016 IEC 2016 3 6.7 Calculation of measured energy 25 6.8 Calculation of
13、 metrics from measured data 25 6.8.1 Calculation of energy performance index and availability 25 6.8.2 Calculation of capacity factor 25 6.8.3 Calculation of performance ratio . 26 6.9 Uncertainty analysis 26 7 Test procedure documentation . 27 8 Test report. 27 Annex A (informative) Example calcula
14、tion Calculations for the energy performance indices 29 Bibliography . 30 Figure 1 Schematic showing relationship of predicted, expected, and measured energies to reflect how the model is applied consistently to historical and measured weather data . 14 Table 1 Example PV performance input parameter
15、s to the model for the initial prediction . 15 Table 2 Example table documenting the meteorological and other input parameters to the model for the calculation of the expected energy 17 Table 3 Example of data filtering criteria, to be adjusted according to local conditions . 20 Table A.1 Fictitious
16、 data to demonstrate calculation . 29 PD IEC/TS 61724-3:2016 4 IEC TS 61724-3:2016 IEC 2016 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ PHOTOVOLTAIC SYSTEM PERFORMANCE Part 3: Energy evaluation method FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for sta
17、ndardization 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 electronic fields. To this end and in addition to other activities, IEC publishes I
18、nternational Standards, Technical Specifications, Technical Reports, Publicly Available 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 partici
19、pate in this preparatory work. International, governmental and non- governmental organizations 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 betw
20、een the two organizations. 2) The formal decisions or agreements of IEC on technical 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 Publicatio
21、ns have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for an
22、y misinterpretation by any end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding
23、 national or regional publication shall be clearly indicated in the latter. 5) IEC 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 serv
24、ices carried out by independent certification bodies. 6) All users should ensure that 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 Nat
25、ional 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 reliance upon, this IEC Publication or any other IEC Publications. 8) Attention
26、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 the elements of this IEC Publication may be the subject of patent rights. IEC sha
27、ll 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 the publication of a technical specification when the required support cannot be
28、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 an agreement on an International Standard. Technical specifications are subject
29、 to review within three years of publication to decide whether they can be transformed into International Standards. IEC TS 61724-3, which is a technical specification, has been prepared by IEC technical committee 82: Solar photovoltaic energy systems. IEC 61724-1, IEC TS 61724-2 and IEC TS 61724-3
30、cancel and replace the first edition of IEC 61724, issued in 1998, and constitute a technical revision. PD IEC/TS 61724-3:2016IEC TS 61724-3:2016 IEC 2016 5 The main technical changes with regard to the first edition of IEC 61724 (1998) are as follows: This first edition of IEC TS 61724-3 provides a
31、 method for quantifying the annual energy generation for a PV plant relative to that expected for the measured weather. The text of this technical specification is based on the following documents: Enquiry draft Report on voting 82/1069/DTS 82/1121/RVC Full information on the voting for the approval
32、 of this technical specification can be found in the report on voting indicated 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 61724 series, published under the general title Photovoltaic system performance, can
33、 be found on the 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 transformed i
34、nto an International standard, reconfirmed, withdrawn, replaced 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 b
35、e useful for the correct understanding of its contents. Users should therefore print this document using a colour printer. PD IEC/TS 61724-3:2016 6 IEC TS 61724-3:2016 IEC 2016 INTRODUCTION The performance of a PV system is dependent on the weather, seasonal effects, and other intermittent issues, s
36、o demonstrating that a PV system is performing as predicted requires determining that the system functions correctly under the full range of conditions relevant to the deployment site. IEC 62446 describes a procedure for ensuring that the plant is constructed correctly and powered on properly by ver
37、ification through incremental tests, but does not attempt to verify that the output of the plant meets the design specification. IEC 61724-1 defines the performance data that may be collected, but does not define how to analyze that data in comparison to predicted performance. IEC TS 61724-2 and AST
38、M E2848-11 describe methods for determining the power output of a photovoltaic system, and are intended to document completion and system turn on, and report a short term power capacity measurement of a PV system, but are not intended for quantifying performance over all ranges of weather or times o
39、f year. IEC 62670-2 also describes how to measure the energy from a CPV plant, but does not describe how to compare the measured energy with a model. The method described in this Technical Specification is intended to address testing of a specific deployed PV system over the full range of relevant o
40、perating conditions and for a sustained time (generally a complete year) to verify long-term expectations of energy production to capture all types of performance issues, including not only response to different weather conditions, but also outages or instances of reduced performance of the plant th
41、at may arise from grid requirements, operational set points, hardware failure, poor maintenance procedures, plant degradation, or other problems. The performance of the system is characterized both by quantifying the energy lost when the plant is not functioning (unavailable) and the extent to which
42、 the performance meets expectations when it is functioning. Multiple aspects of PV system performance are dependent on both the weather and the system quality, so it is essential to have a clear understanding of the system being tested. For example, the module temperature is primarily a function of
43、irradiance, ambient temperature, and wind speed; all of which are weather effects. However, the module-mounting configuration also affects the module temperature, and the mounting is an aspect of the system that is being tested. This technical specification presents a best-practice process for test
44、development and clarifies how measurement choices can affect the outcome of the test so that users can benefit from streamlined test design with consistent definitions, while still allowing flexibility in the application of the test so as to accommodate as many unique installations as possible. IECR
45、Es Annual PV Project Performance Certificate incorporates measurements from this Technical Specification. Although this technical specification allows application in multiple ways, to maintain a consistent definition of the meaning of the IECRE certificate, when this technical specification is used
46、for measurements for IECRE reporting, the method may be required to use a minimum level of accuracy for the measurements or other details as documented by IECRE. PD IEC/TS 61724-3:2016IEC TS 61724-3:2016 IEC 2016 7 PHOTOVOLTAIC SYSTEM PERFORMANCE Part 3: Energy evaluation method 1 Scope This part of
47、 IEC 61724, which is a Technical Specification, defines a procedure for measuring and analyzing the energy production of a specific photovoltaic system relative to expected electrical energy production for the same system from actual weather conditions as defined by the stakeholders of the test. The
48、 method for predicting the electrical energy production is outside of the scope of this technical specification. The energy production is characterized specifically for times when the system is operating (available); times when the system is not operating (unavailable) are quantified as part of an a
49、vailability metric. For best results, this procedure should be used for long-term performance (electrical energy production) testing of photovoltaic systems to evaluate sustained performance of the system over the entire range of operating conditions encountered through the duration of the test (preferably one year). Such an evaluation provides evidence that long-term expectations of system energy production are accurate and covers all environmental effects at the site. In addition, for the year,
