EN IEC 62933-3-1:2026
(Main)Electrical energy storage (EES) systems - Part 3-1: Planning and performance assessment of electrical energy storage systems - General specification
Electrical energy storage (EES) systems - Part 3-1: Planning and performance assessment of electrical energy storage systems - General specification
IEC 62933-3-1:2025 is applicable to EES systems designed for grid-connected indoor or outdoor installation and operation. This document considers: necessary functions and capabilities of EES systems; sizing and design of EES system; operation of EES system; test items and performance assessment methods for EES systems; requirements for monitoring and acquisition of EES system operating parameters; exchange of system information and control capabilities required; maintenance of EES system. Stakeholders of this document comprise personnel involved with EES systems, which include: - planners of electric power systems and EES systems; - owners of EES systems; - operators of electric power systems and EES systems; - constructors; - suppliers of EES systems and its equipment; - aggregators. Use-case-specific technical documentation, including planning and installation specific tasks such as system design, monitoring, measurement, tests, operation and maintenance, are very important and can be found throughout this document.
Elektrische Energiespeichersysteme - Teil 3-1: Planung und Leistungsbewertung von elektrischen Energiespeichersystemen - Allgemeine Festlegungen
Systèmes de stockage de l’énergie électrique (EES) - Partie 3-1: Planification et évaluation des performances des systèmes de stockage de l’énergie électrique - Spécifications générales
IEC 62933-3-1:2025 s'applique aux systèmes EES connectés au réseau et conçus être installés et fonctionner en intérieur ou en extérieur. Le présent document examine: - les fonctions et les capacités nécessaires des systèmes EES; - le dimensionnement et la conception des systèmes EES; - le fonctionnement des systèmes EES; - les éléments d'essai et les méthodes d'évaluation des performances des systèmes EES; - les exigences pour la surveillance et l'acquisition des paramètres de fonctionnement des systèmes EES; - l’échange d'informations entre les systèmes et les capacités de commande exigées; - la maintenance des systèmes EES. Les parties prenantes du présent document sont le personnel impliqué dans les systèmes EES, notamment: - les planificateurs de réseaux d’énergie électrique et de systèmes EES; - les propriétaires de systèmes EES; - les opérateurs de réseaux d’énergie électrique et de systèmes EES; - les constructeurs; - les fournisseurs de systèmes EES et des équipements associés; - les agrégateurs. La documentation technique spécifique à chaque cas d'utilisation, y compris les tâches spécifiques à la planification et à l'installation telles que la conception, la surveillance, le mesurage, les essais, le fonctionnement et la maintenance du système, est très importante et est spécifiée tout au long du présent document
Električne naprave za shranjevanje energije (EES) - 3-1. del: Načrtovanje in ocenjevanje delovanja sistemov za shranjevanje električne energije - Splošna specifikacija
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN IEC 62933-3-1:2024
01-oktober-2024
Električne naprave za shranjevanje energije (EES) - 3-1. del: Načrtovanje in
ocenjevanje delovanja sistemov za shranjevanje električne energije - Splošna
specifikacija
Electrical energy storage (EES) systems - Part 3-1: Planning and performance
assessment of electrical energy storage systems - General specification
Ta slovenski standard je istoveten z: prEN IEC 62933-3-1:2024
ICS:
13.020.30 Ocenjevanje vpliva na okolje Environmental impact
assessment
oSIST prEN IEC 62933-3-1:2024 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
oSIST prEN IEC 62933-3-1:2024
oSIST prEN IEC 62933-3-1:2024
120/376/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 62933-3-1 ED1
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2024-08-09 2024-11-01
SUPERSEDES DOCUMENTS:
120/328/CD, 120/344/CC
IEC TC 120 : ELECTRICAL ENERGY STORAGE (EES) SYSTEMS
SECRETARIAT: SECRETARY:
Japan Mr Masatake SAKUMA
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:
TC 8,TC 21,TC 22,TC 57,TC 69
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.
Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some
Countries” clauses to be included should this proposal proceed. Recipients are reminded that the CDV stage is the
final stage for submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).
TITLE:
Electrical energy storage (EES) systems - Part 3-1: Planning and performance assessment of
electrical energy storage systems - General specification
PROPOSED STABILITY DATE: 2031
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 62933-3-1:2024
IEC CDV 62933-3-1 © IEC 2024 2 120/376/CDV
NOTE FROM TC/SC OFFICERS:
TC 120 Secretary checked 120/328/CD, 120/344/CC and CDV Word file respectively and the update
was confirmed.
oSIST prEN IEC 62933-3-1:2024
120/376/CDV 3 IEC CDV 62933-3-1 © IEC 2024
1 CONTENTS
2 CONTENTS . 3
3 FOREWORD . 8
4 INTRODUCTION . 10
5 1 Scope . 11
6 2 Normative references . 11
7 3 Terms, definitions and symbols. 12
8 3.1 Terms and definitions . 12
9 3.2 Symbols . 12
10 4 General about EES systems . 13
11 4.1 Main functional aspects . 13
12 4.2 Architecture of an EES system . 13
13 4.3 Subsystem specifications . 14
14 4.3.1 General . 14
15 4.3.2 Accumulation subsystem . 15
16 4.3.3 Power conversion subsystem . 16
17 4.3.4 Auxiliary subsystem . 17
18 4.3.5 Control subsystem . 17
19 4.4 Main electrical parameters of EES systems . 19
20 4.4.1 General . 19
21 4.4.2 Active input and output power rating . 19
22 4.4.3 Rated energy storage capacity . 20
23 4.4.4 Response time performances . 20
24 4.4.5 Rated reactive power . 20
25 4.4.6 Auxiliary power consumption . 21
26 4.4.7 Self-discharge . 21
27 4.4.8 Roundtrip efficiency . 21
28 4.4.9 Duty cycle roundtrip efficiency . 21
29 4.4.10 Recovery time . 21
30 4.4.11 Asset lifetime and end-of-service life values . 21
31 5 Planning and design of EES systems . 23
32 5.1 General . 23
33 5.2 Overview EES system planning and design process . 23
34 5.3 Functional purpose and applications of EES systems . 26
35 5.3.1 General . 26
36 5.3.2 Power intensive applications . 26
37 5.3.3 Renewable energy sources integration related applications . 26
38 5.3.4 Energy intensive applications . 27
39 5.3.5 Backup power applications . 27
40 5.3.6 Multi-function applications . 27
41 5.4 Duty cycle at primary POC . 28
42 5.5 Selection of the EES system and preliminary sizing . 30
43 5.5.1 Requirements and constraints for EES system sizing . 30
44 5.5.2 Preliminary sizing procedure according to duty cycle and primary POC . 33
oSIST prEN IEC 62933-3-1:2024
IEC CDV 62933-3-1 © IEC 2024 4 120/376/CDV
45 5.6 EES system environment . 35
46 5.6.1 General . 35
47 5.6.2 Grid parameters and requirements . 35
48 5.6.3 Grid integration of the EES systems . 36
49 5.6.4 Service conditions . 37
50 5.6.5 Standards and local regulations . 39
51 5.7 Conditions and requirements for connection to the grid . 40
52 5.7.1 Requirements and restrictions of the grid or system operator . 40
53 5.8 Operational requirements . 41
54 5.8.1 Monitoring . 41
55 5.8.2 Maintenance . 43
56 5.9 Final sizing . 43
57 5.9.1 Considerations for final sizing . 43
58 5.9.2 Final sizing results . 51
59 5.10 Control subsystem . 53
60 5.10.1 Control subsystem aspects . 53
61 5.10.2 Operation states of control subsystem . 54
62 5.10.3 Operation and control . 62
63 5.11 Communication interface. 63
64 5.11.1 Communication interface (to external systems) . 63
65 5.11.2 Information model for an EES system . 63
66 5.11.3 Remote monitoring and control . 65
67 6 Performance assessment and service life of EES system . 71
68 6.1 Factory acceptance test (FAT) . 71
69 6.2 Installation and commissioning . 71
70 6.2.1 General . 71
71 6.2.2 Installation phase . 72
72 6.2.3 Commissioning phase . 73
73 6.3 Site acceptance test (SAT) . 75
74 6.4 Lifetime of EES systems . 75
75 6.4.1 General . 75
76 6.4.2 Performance assessment . 75
77 6.4.3 Performance monitoring phase . 76
78 6.5 EES system decommissioning . 77
79 6.6 Inspection and test aspects . 77
80 Annex A (informative) EES system applications . 82
81 A.1 EES system for power support at an electric charging station . 82
82 A.2 EES system designed for frequency control . 84
83 A.2.1 General . 84
84 A.2.2 Example of an EES system for primary frequency control . 84
85 A.2.3 Example of an EES system for secondary frequency control . 86
86 A.2.4 Example of an EES system for dynamic frequency control . 87
87 A.3 EES system in conjunction with renewable energy production . 89
88 A.3.1 General . 89
89 A.3.2 Example of EES system for renewable (energy) firming . 89
oSIST prEN IEC 62933-3-1:2024
120/376/CDV 5 IEC CDV 62933-3-1 © IEC 2024
90 A.3.3 Example of EES system for renewable (power) smoothing . 90
91 A.3.4 Example of EES system in PV-EESS-EV charging station application . 91
92 A.3.5 Example of EES system as a black start resource for PV plant . 93
93 A.4 EES system for grid support applications . 93
94 A.4.1 Example of an EES system for grid voltage support (Q(U) control mode) . 93
95 A.4.2 Example of an EES system for power quality support by voltage-related
96 active power injection . 96
97 Annex B (informative) Aspects to be considered with regard to EES system installation . 98
98 B.1 Feasibility and permission . 98
99 B.2 Basic planned activities for feasibility study . 99
100 B.2.2 Permitting process . 100
101 B.3 Site-assembling . 101
102 B.4 Protection against disaster – Fire prevention . 101
103 B.5 Transportation and on-site storage . 101
104 Annex C (informative) Aspects to be considered with regard to EES system
105 decommissioning . 102
106 C.1 General . 102
107 C.2 Decommissioning Plan . 103
108 C.2.1 Phase - EES system description and notification . 104
109 C.2.2 Phase – Estimation of decommissioning cost . 104
110 C.2.3 Phase - EES system decommissioning. 104
111 C.2.4 Phase - EES system material and components removal and recycling . 105
112 C.2.5 Phase – EES system dismantling, demolition, removing, packing and site
113 clearance . 106
114 C.2.6 Phase – EES system site rehabilitation . 106
115 Bibliography . 108
117 Figure 1 – Typical architectures of EES systems . 14
118 Figure 2 – Example of classification of EES systems according to energy form . 15
119 Figure 3 – EES system typical architecture with detailed structure of management
120 subsystem . 18
121 Figure 4 – Sample performance versus time characteristics for EES systems . 22
122 Figure 5 – Sample consideration to design the service life of EES systems . 22
123 Figure 6 – Overview about the aspects of planning of EES systems . 24
124 Figure 7 – Overview of EES system sizing process . 26
125 Figure 8 – Example of EES planning process with multi-scenario applications . 28
126 Figure 9 – Determination of auxiliary power for an EES system without auxiliary POC . 46
127 Figure 10 –Example of EES system operation states . 55
128 Figure 11 – Example for P(f) strategy . 57
129 Figure 12 – Example of setting of active output power at primary POC . 58
130 Figure 13 – Example of day pattern operation at primary POC . 59
131 Figure 14 – Example of peak shaving application . 60
132 Figure 15 – Example of a general control characteristic . 61
133 Figure 16 – Reference diagram for information exchange . 64
oSIST prEN IEC 62933-3-1:2024
IEC CDV 62933-3-1 © IEC 2024 6 120/376/CDV
134 Figure 17 – EES system as an aggregation of several EES systems at the same
135 primary POC . 64
136 Figure 18 – Example of an information model hierarchy of an EES system . 67
137 Figure A.1 – Sample requirements for an EES system at an electric charging station . 82
138 Figure A.2 – Design duty cycle of an EES system at an electric charging station . 84
139 Figure A.3 – Sample duty cycle for a primary frequency control application with 30-s
140 power output every 30 min shown over 2 h . 85
141 Figure A.4 – Sample power output for a secondary frequency control application with
142 20-min power output over 3 h . 87
143 Figure A.5 – Sample output power of an EES system for a dynamic frequency control
144 application in spring, summer, autumn and winter . 88
145 Figure A.6 – Sample output power of an EES system in a renewable (solar) energy
146 firming application . 90
147 Figure A.7 – Sample output power of an EES system for a renewable (solar) power
148 smoothing application . 91
149 Figure A.8 – Sample output power of an EES system for an PV-EESS-EV charging
150 station application . 92
151 Figure A.9 – Bus voltages and active power of the PV plant in black start of the PV
152 plant with BESS . 93
153 Figure A.10 – Example of grid voltage at the POC of a photovoltaic power plant . 94
154 Figure A.11 – Sample reactive power supply of an EES system at the POC . 95
155 Figure A.12 – Sa Sample duty cycle for power quality support by voltage-related active
156 power injection with 5-min power output every 45 min over 12 h . 97
157 Figure B.1: Typical phases in the project cycle management . 98
158 Figure C.1: Typical phases in the project cycle management . 102
160 Table 1 – Points of attention for planning phase. 19
161 Table 2 – Typical multi-scenario applications of EES systems . 28
162 Table 3 – Example of day pattern operation . 59
163 Table 4 – Example for messages of measurement and monitoring categories versus
164 categories of messages . 66
165 Table 5 – Example of messages of an EES system information model . 67
166 Table 6 – Example of items to be taken into account. 72
167 Table 7 – Points of attention for commissioning phase (parameter tests) . 74
168 Table 8 – Points of attention for performance monitoring phase . 76
169 Table 9 – Example of local measurements and monitoring of EES system . 77
170 Table 10 – Example of inspection items for EES system and its subsystems classified
171 according to different points of time in the service life time . 78
172 Table A.1 – Sample design duty cycle and sizing values of an EES system at an
173 electric charging station . 83
174 Table A.2 –Sample values of a duty cycle for primary frequency control for sudden
175 loss of generation . 86
176 Table A.3 – Sample values of recovery time for primary frequency control for sudden
177 loss of generation . 86
oSIST prEN IEC 62933-3-1:2024
120/376/CDV 7 IEC CDV 62933-3-1 © IEC 2024
178 Table A.4 – Sample values of a duty cycle for secondary frequency control for sudden
179 loss of generation . 87
180 Table A.5 – Sample values of a duty cycle for dynamic primary frequency control. 89
181 Table A.6 – Sample values of a duty cycle for renewable (energy) firming . 90
182 Table A.7 – EES system’s operation mode for the case of a commercial charging
183 station based on common AC bus . 92
184 Table A.8 – Sample values of a duty cycle for a commercial PV-EESS-EV charging
185 station . 92
186 Table A.9 – Sample values of a duty cycle for grid voltage support by Q(U) control
187 mode . 96
188 Table A.10 – Sample values of a duty cycle for power quality . 97
oSIST prEN IEC 62933-3-1:2024
IEC CDV 62933-3-1 © IEC 2024 8 120/376/CDV
190 INTERNATIONAL ELECTROTECHNICAL COMMISSION
191 ____________
193 ELECTRICAL ENERGY STORAGE (EES) SYSTEMS –
195 Part 3-1: Planning and performance assessment of
196 electrical energy storage systems – General specification
198 FOREWORD
199 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
200 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
201 international co-operation on all questions concerning standardization in the electrical and electronic fields. To
202 this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
203 Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
204 Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
205 in the subject dealt with may participate in this preparatory work. International, governmental and non-
206 governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
207 with the International Organization for Standardization (ISO) in accordance with conditions determined by
208 agreement between the two organizations.
209 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
210 consensus of opinion on the relevant subjects since each technical committee has representation from all
211 interested IEC National Committees.
212 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
213 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
214 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
215 misinterpretation by any end user.
216 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
217 transparently to the maximum extent possible in their national and regional publications. Any divergence
218 between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
219 the latter.
220 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
221 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
222 services carried out by independent certification bodies.
223 6) All users should ensure that they have the latest edition of this publication.
224 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
225 members of its technical committees and IEC National Committees for any personal injury, property damage or
226 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
227 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
228 Publications.
229 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
230 indispensable for the correct application of this publication.
231 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
232 patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
233 The main task of IEC technical committees is to prepare International Standards. In
234 exceptional circumstances, a technical committee may propose the publication of a technical
235 specification when
236 • the required support cannot be obtained for the publication of an International Standard,
237 despite repeated efforts, or
238 • the subject is still under technical development or where, for any other reason, there is the
239 future but no immediate possibility of an agreement on an International Standard.
oSIST prEN IEC 62933-3-1:2024
120/376/CDV 9 IEC CDV 62933-3-1 © IEC 2024
240 Technical Specification IEC 62933-3-1 has been prepared by IEC technical committee TC 120:
241 Electrical Energy Storage (EES) Systems.
242 The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
120/118/DTS 120/123/RVDTS
244 Full information on the voting for the approval of this technical specification can be found in
245 the report on voting indicated in the above table.
246 This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
247 A list of all parts in the IEC 62933 series, published under the general title Electrical energy
248 storage (EES) systems, can be found on the IEC website.
249 The committee has decided that the contents of this publication will remain unchanged until
250 the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
251 related to the specific publication. At this date, the publication will be
252 • transformed into an International standard,
253 • reconfirmed,
254 • withdrawn,
255 • replaced by a revised edition, or
256 • amended.
257 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 should therefore print this document using a
colour printer.
oSIST prEN IEC 62933-3-1:2024
IEC CDV 62933-3-1 © IEC 2024 10 120/376/CDV
261 INTRODUCTION
262 IEC 62933-2-1 should be used as a reference when selecting testing items and their
263 corresponding evaluation methods as well as principal parameters. Principal terms used in
264 this document are defined in IEC 62933-1. Environmental issues are covered by
265 IEC TS 62933-4-1. The personnel safety issues are covered by IEC TS 62933-5-1.
oSIST prEN IEC 62933-3-1:2024
120/376/CDV 11 IEC CDV 62933-3-1 © IEC 2024
268 ELECTRICAL ENERGY STORAGE (EES) SYSTEMS –
270 Part 3-1: Planning and performance assessment of
271 electrical energy storage systems – General specification
273 1 Scope
274 This part of IEC 62933 is applicable to EES systems designed for grid-connected indoor or
275 outdoor installation and operation. This document considers
276 • necessary functions and capabilities of EES systems
277 • sizing and design of EES system
278 • operation of EES system
279 • test items and performance assessment methods for EES systems
280 • requirements for monitoring and acquisition of EES system operating parameters
281 • exchange of system information and control capabilities required
282 • maintenance of EES system
283 Stakeholders of this document comprise personnel involved with EES systems, which include
284 – planners of electric power systems and EES systems
285 – owners of EES systems
286 – operators of electric power systems and EES systems
287 – constructors
288 – suppliers of EES systems and its equipment
289 – aggregators
290 Use-case-specific technical documentation, including planning and installation specific tasks
291 such as system design, monitoring, measurement, tests, operation and maintenance, are very
292 important and can be found throughout this document.
293 NOTE This document has been written for AC grids, however parts can also apply to DC grids.
294 2 Normative references
295 The following documents are referred to in the text in such a way that some or all of their
296 content constitutes requirements of this document. For dated references, only the edition
297 cited applies. For undated references, the latest edition of the referenced document (including
298 any amendments) applies.
299 IEC 60721-1, Classification of environmental conditions – Part 1: Environmental parameters
300 and their severities
301 IEC 61850-7-420, Communication networks and systems for power utility automation –Part 7-
302 420: Basic communication structure – Distributed energy resources logical nodes
oSIST prEN IEC 62933-3-1:2024
IEC CDV 62933-3-1 © IEC 2024 12 120/376/CDV
303 IEC 62351 (all parts), Power systems management and associated information exchange –
304 Data and communications security
305 IEC 62443 (all parts), Industrial communication networks – Network and system security
306 IEC 62933-1, Electrical energy storage (EES) systems – Part 1: Vocabulary
307 IEC 62933-2-1, Electrical energy storage (EES) systems – Part 2-1: Unit parameters and
308 testing methods – General specification
309 IEC TS 62933-5-1, Electrical energy storage (EES) systems – Part 5-1: Safety considerations
310 for grid-integrated EES systems – General specification
311 ISO/IEC 27000, Information technology – Security techniques – Information security
312 management systems – Overview and vocabulary
313 3 Terms, definitions and symbols
314 3.1 Terms and definitions
315 For the purposes of this document, the terms and definitions given in IEC 62933-1 and the
316 following apply.
317 ISO and IEC maintain terminological databases for use in standardization at the following
318 addresses:
319 • IEC Electropedia: available at http://www.electropedia.org
320 • ISO Online browsing platform: available at http://www.iso.org/obp
321 Note 1 to entry: The definition is loosely based on IEC 60050-447:2010, 447-05-08.
323 3.2 Symbols
324 cosφ power factor
325 E energy
326 E energy storage capacity
C
327 ɳ efficiency
328 f frequency
329 I current
330 P active power
331 Q reactive power
332 S apparent power
333 SOH state of energy
334 SOH state of health
335 U voltage
oSIST prEN IEC 62933-3-1:2024
120/376/CDV 13 IEC CDV 62933-3-1 © IEC 2024
336 4 General about EES systems
337 4.1 Main functional aspects
338 According to IEC 62933-1 an EES system is a grid-connected installation with defined
339 electrical boundaries, comprising at least one electrical energy storage unit, which extracts
340 electrical energy from an electric power system, stores this energy internally in some manner
341 and injects electrical energy into an electric power system. An EES system can include civil
342 engineering works, energy conversion equipment and related ancillary equipment. The EES
343 system is controlled and coordinated to provide services to the electric power system
344 operators or to the electric power system users.
345 4.2 Architecture of an EES system
346 The typical architecture of an EES system, which internally feeds the auxiliary subsystem, is
347 given in Figure 1 a).
oSIST prEN IEC 62933-3-1:2024
IEC CDV 62933-3-1 © IEC 2024 14 120/376/CDV
349 a) EES system without auxiliary POC
351 b) EES system with auxiliary POC
352 Figure 1 – Typical architectures of EES systems
353 If the auxiliary subsystem is fed from another feeder, the optional architecture of an ESS
354 system is shown in Figure 1 b).
355 4.3 Subsystem specifications
356 4.3.1 General
357 To meet the requirements of the entire EES system, it is necessary to break down the system
358 requirements to the requirements of the subsystems. The requirements for the subsystems
359 shall be formulated in a general and technology-independent manner. But requirements
360 arising from the subsystems (e.g. regarding safety or maintenance), which are technology
361 dependent, shall also be considered.
362 Constrains and deratings regarding power rating, available energy, ambient conditions and
363 other internal/external aspects shall also be considered for all subsystems.
oSIST prEN IEC 62933-3-1:2024
120/376/CDV 15 IEC CDV 62933-3-1 © IEC 2024
364 The requirements of the subsystems of an EES system are described in sub-clauses 4.3.2 to
365 4.3.5. In general, for all subsystems, the contribution to the overall system efficiency, for
366 example roundtrip efficiency, shall be indicated.
367 4.3.2 Accumulation subsystem
368 The energy storage capacity of the accumulation subsystem of the EES system has to be
369 evaluated in an appropriate way with respect to the energy form (e.g. mechanical or
370 electrochemical). The energy storage capacity of the accumulation subsystem directly
371 influences the rated input and output energy capacity at the primary POC, i.e. it influences the
372 active input and output power values at the primary POC as well as the duration the active
373 input and output power can be applied at the primary POC.
374 A widely-used approach for classifying EES systems is the determination according to the
375 form of energy used in the accumulation subsystem. A classification example of EES systems
376 according to energy form in the accumulation subsystem is shown in Figure 2.
EES systems
Mechanical Electrochemical Electrical
Double-layer
Secondary batteries
Pumped hydro – PHS
Lead acid/NiCd/NiMH/Li/NaS capacitor – DLC
Compressed air – CAES Flow batteries Superconducting
Redox flow/hybrid flow
magnetic coil – SMES
Flywheel – FES
Chemical
Thermal
Hydrogen Sensible heat storage
Gravimetric storage
Electrolyser/fuel cell/SNG
Molten salt/A-CAES
IEC
378 Figure 2 – Example of classification of EES systems according to energy form
379 Accumulation subsystems shall meet performance specifications such as enough energy
380 storage capacity throughout their service life. This includes their service life under use
381 conditions such as operation patterns (see IEC 62933-1:2018, Figure 1), environmental
382 conditions, maintenance cycle, etc.
384 a) General requirements
385 The following information shall be provided irrespective of the technology applied:
386 For each accumulation subsystem the energy storage capacity and the maximum charge and
387 discharge power shall be considered because this has a direct influence on the overall EES
388 system.
389 Also, the present energy content is important for the EES system. A forecast method, i.e. how
390 the resulting energy content after charging or discharging with a certain power for a certain
391 time can be estimated, shall be given.
oSIST prEN IEC 62933-3-1:2024
IEC CDV 62933-3-1 © IEC 2024 16 120/376/CDV
392 Typical service life values (possibly differentiated into cyclical and calendrical ageing) shall be
393 specified. Information on the energy and power density shall also be given to be able to make
394 a comparison with other accumulation subsystems if necessary.
395 Information about necessary service and maintenance cycles shall be given. The auxiliary
396 power demand of the accumulation subsystem shall also be provided, if applicable.
397 Furthermore, efficiency parameters of the accumulation subsystem shall be provided:
398 • charging efficiency of the accumulation subsystem;
399 • discharging efficiency of the accumulation subsystem;
400 • self-discharge or “energy storage efficiency” of the accumulation subsystem.
401 b) Specific requirements
402 If there are requirements that are specific to the accumulation technology applied, then these
403 requirements shall be provided. For example, if a reduction in charging or discharging power
404 is necessary in certain operating areas, this shall be indicated. If special regulations have to
405 be considered for the accumulation subsystem (for example, for disposal), this shall be
406 specified, as it could be relevant for planning. If galvanic isolation between POC and
407 accumulation subsystem is provided, this shall also be given.
408 4.3.3 Power conversion subsystem
409 The power conversion subsystem converts the power of the accumulation subsystem into
410 electrical power at the POC, typically AC output power during discharge of the accumulation
411 subsystem and can convert grid AC input power to suitable power for charging the
412 accumulation subsystem. This conversion can be performed by electrical and/or mechanical
413 systems. The power conversion subsystem influences the apparent power characteristic of
414 the EES system. The power conversion subsystem can also influence the power quality at the
415 POC.
416 Generally, the power conversion subsystem is connected to the accumulation subsystem and
417 to the (primary) connection terminal. For planning issues, the power conversion subsystem
418 shall also include all power transfer apparatus between the connection terminal and the
419 accumulation subsystem, for example any kind of power transformer, sine filter or switching
420 elements.
421 a) General requirements
422 The following information shall be provided irrespective of the technology applied:
423 The auxiliary power demand of the power conversion subsystem shall be given, if applicable.
424 If galvanic isolation between the POC and accumulation subsystem is provided, this shall also
425 be stated. Furthermore, efficiency parameters of the conversion subsystem shall be provided:
426 • charging efficiency of the power conversion subsystem;
427 • discharging efficiency of the power conversion subsystem.
428 b) Specific requirements
429 If there are requirements that are specific to the power conversion technology applied, then
430 these requirements shall be provided. For example, if the voltage and frequency of an
431 electrical power grid are set by the power conversion subsystem using grid forming
432 technology, specific requirements shall be given. The conversion type (AC/DC, AC/AC,
oSIST prEN IEC 62933-3-1:2024
120/376/CDV 17 IEC CDV 62933-3-1 © IEC 2024
433 pump/generator, etc.) as well as the operational ranges, for example the DC voltage or
434 frequency range, shall be given.
435 4.3.4 Auxiliary subsystem
436 All necessary equipment intended to perform the EES system’s auxiliary functions shall be
437 considered, for example, HVAC (heating, ventilation, and air conditioning system) and fire
438 suppression system.
439 a) General requirements
440 The following information shall be provided irrespective of the technology applied:
441 The overall auxiliary power demand of the EES system which has to be handled by the
442 auxiliary subsystem shall be given. Auxiliary power demand for every noteworthy operational
443 state of the EESS shall be provided. Information regarding the structure of the auxiliary
444 subsystem shall be given.
445 Furthermore, requirements regarding redundancy and buffered power supply (in case of an
446 outage of the supplying power source) shall be provided, if applicable.
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.