EN 61427-2:2015/A1:2024

SLOVENSKI STANDARD
oSIST prEN IEC 61427-2:2023
01-junij-2023
Sekundarni členi in baterije za shranjevanje obnovljive energije - Splošne zahteve
in preskusne metode - 2. del: Omrežne izvedbe
Secondary cells and batteries for renewable energy storage - General requirements and
methods of test - Part 2: On-grid applications
Wiederaufladbare Zellen und Batterien für die Speicherung erneuerbarer Energien -
Allgemeine Anforderungen und Prüfverfahren - Teil 2: Netzgekoppelte Anwendungen
Accumulateurs pour le stockage de l'énergie renouvelable - Exigences générales et
méthodes d'essais - Partie 2: Applications en réseau
Ta slovenski standard je istoveten z: prEN IEC 61427-2:2023
ICS:
27.160 Sončna energija Solar energy engineering
29.220.20 Kislinski sekundarni členi in Acid secondary cells and
baterije batteries
oSIST prEN IEC 61427-2:2023 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN IEC 61427-2:2023
oSIST prEN IEC 61427-2:2023
21/1166/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 61427-2 ED1/AMD1*
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2023-04-21 2023-07-14
SUPERSEDES DOCUMENTS:
21/1159/CD, 21/1165/CC
IEC TC 21 : SECONDARY CELLS AND BATTERIES
SECRETARIAT: SECRETARY:
France Mr Yves BOUDOU
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

SC 21A,TC 82,TC 88,TC 120
Other TC/SCs are requested to indicate their interest, if
any, in this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft for
Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of
• any relevant patent rights of which they are aware and to provide supporting documentation ,
• any relevant “in some countries” clauses to be included should this proposal proceed. Recipients are remin ded
that the enquiry stage is the final stage for submitting "in some countries" clauses. See AC/22/2007.

TITLE:
Secondary cells and batteries for renewable energy storage - General requirements and methods of
test - Part 2: On-grid applications

PROPOSED STABILITY DATE: 2027
NOTE FROM TC/SC OFFICERS:
*Please be informed that the project was erroneously registered as an ED2 instead of an Amendment 1 to
ED1. Please note that the project number has been updated accordingly.
this electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee
positions. You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose
without permission in writing from IEC.

oSIST prEN IEC 61427-2:2023
-2- 21/1166/CDV
1 IEC CDV for 61427-2: Amendment 1. © IEC 2023
3 Text to be added at the end of clause 6.1 in the main body of the standard.
5 6 Battery endurance
7 6.1 General
8 to be added at end of clause 6.1
10 Since the publication of IEC 61427-2 in 2015, details of a complex pattern of energy exchange in frequency-
11 regulation duty, at 4 s intervals and over a 24 h period, has been published in the PNNL-22010 Rev 2/ SAND
12 2016-3078 R Report.
14 In Annex B (informative) details of this energy exchange profile are made available for evaluating, if useful, the
15 service-induced decay of battery performance also with a more randomized usage pattern compared to that
16 offered by the symmetric 6.2 profile.
18 Text to be added after Annex A
19 Annex B
20 (Informative)
22 B.1 Introduction
24 The batteries in on-grid electrical energy storage (EES) applications provide and accept the energy needed to
25 maintain the mains frequency within specified limits. This exchange of energy results in multiple charge and
26 discharge events per hour in the electrochemically active masses of the battery. The order, intensity and
27 duration of these events influences the stability and activity of the involved active mass structures and hence
28 the endurance of the batteries.
30 This additional test procedure for evaluating battery performance under frequency-regulation service, is based
31 on data acquired by actual monitoring of a regional transmission organization grid frequency balancing signal
32 by Pacific Northwest National Laboratory (PNNL) and Sandia National Laboratories (SAND) in the USA.
34 The balancing signal data are reported in section 5.3.2 Frequency regulation duty cycle of the document PNNL-
35 22010 Rev 2 / SAND 2016-3078 R - Protocol for Uniformly Measuring and Expressing the Performance of
36 Energy Storage Systems and dated April 2016.
38 The complex pattern of energy exchange and the associated procedures described in B.2, can be used as a
39 tool to complement and reinforce, as appropriate or useful, the information on the service-induced decay of
40 battery performance gathered with the test profile in 6.2. The profile in 6.2 remains however the normative
41 profile if product comparisons or qualifications are carried out.
43 The test and associated test profile specified in B.3 is optional; it is not necessary to carry it out to claim
44 conformance with the document.
46 However, if this test is carried out, it shall be executed as specified in B.3.
48 B.2 The Annex B profile for evaluating battery endurance in frequency-regulation duty
50 The Annex B profile consists in a sequence of 2 h average and 2 h aggressive signal levels reflecting the
51 deviation from the grid frequency dead band and the resulting demand to deliver energy from or store in the
52 battery of the frequency-regulation application. Each signal specifies a constant power level for a duration of
53 4s resulting in 1800 signal levels per 2 h period. The adjective of average and aggressive reflects the intensity
54 of the energy flow to and from the battery.
56 Over 24 h, the Annex B duty cycle consists of a sequence with three 2-hour duration average signal deviation
57 levels, one 2-hour duration aggressive signal deviation level, three 2-hour duration average signal deviation
58 levels, one 2-hour duration aggressive signal deviation level and four 2-hour duration average signal deviation

oSIST prEN IEC 61427-2:2023
-3- 21/1166/CDV
59 levels. The values of average and aggressive deviation signal level, forming the 24h duty cycle as shown in
60 Figure B.1, are listed in a spreadsheet.
62 The file containing the spreadsheet is available for download on the IEC platform via
63 https://collaborate.iec.ch/#/pages/workspaces/200650/documents/63751/details/691813?onlyWithPreview=false&fileId=691813
+η
Type equation here.
avg agg avg agg avg
-η
Type equation here.
Elapsed time in hours
82 Figure B.1 – 24 h sequence of the Annex B profile for a supplemental evaluation of the
83         service-induced performance decay of a battery in frequency-regulation service
85 The exchanged power η is normalized with respect to the rated power of the EES application where the positive
86 value represents a discharge from the battery and negative value a charge into the battery.
88 The longest duration at full discharge power or η = 1.0 is 52 s. The daily averaged power level is 30 % of the
89 rated power capability of the EES system. The amount of energy charged daily into the battery (Wh-in) is equal
90 to the daily amount of energy discharged (Wh-out).
92 This will result, due to a roundtrip Wh efficiency of <1.0, in a slow walk-down of the battery capacity over time
93 requiring periodic auxiliary charge energy input to re-establish the proper target level of operational state of
94 charge (SoCOT) required to fulfil all peak power demands. The SoCOT level is specific for each type of battery
95 and application and is specified by the battery manufacturer.
97 It is recommended that the machine instructions or commands for the power levels during a full 24h-duration
98 duty cycle, are broken down into the appropriate consecutive sequences of 2 h with 1800 signal levels each.
99 This facilitates the upload and the execution of the power level setting instructions by the control unit of the
100 battery cycling equipment.
102 The overall composite 24 h instruction set is the following
104 Start the 24h sequence
105 - Go to data set of a 2h sequence at average power level and execute set 3 times
106 - Go to data set of a 2h sequence at aggressive power level and execute set 1 time
107 - Go to
...