prEN IEC 60205:2024

SLOVENSKI STANDARD
01-junij-2024
Izračun efektivnih parametrov magnetnih sestavnih delov
Calculation of the effective parameters of magnetic piece parts
Berechnung der effektiven Kernparameter magnetischer Formteile
Calcul des paramètres effectifs des pièces magnétiques
Ta slovenski standard je istoveten z: prEN IEC 60205:2024
ICS:
29.100.10 Magnetne komponente Magnetic components
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

51/1486/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60205 ED5
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2024-04-12 2024-07-05
SUPERSEDES DOCUMENTS:
51/1456/CD, 51/1478/CC
IEC TC 51 : MAGNETIC COMPONENTS, FERRITE AND MAGNETIC POWDER MATERIALS
SECRETARIAT: SECRETARY:
Japan Mr Naoki Kawakubo
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

Other TC/SCs are requested to indicate their interest, if
any, in this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY

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CENELEC, is drawn to the fact that this Committee Draft
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The CENELEC members are invited to vote through the
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final stage for submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Calculation of the effective parameters of magnetic piece parts

PROPOSED STABILITY DATE: 2030
NOTE FROM TC/SC OFFICERS:
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.

IEC CDV 60205 © IEC 2024 2 51/1486/CDV

1 CONTENTS
3 FOREWORD . 4
4 1 Scope . 6
5 2 Normative references . 6
6 3 Terms and definitions . 6
7 4 Basic rules applicable to this standard . 6
8 5 Formulae for the various types of cores . 7
9 5.1 Ring cores . 7
10 5.1.1 Ring cores in general . 7
11 5.1.2 For ring cores of rectangular cross-section with sharp corners . 8
12 5.1.3 For ring cores of rectangular cross-section with an appreciable average
13 rounding radius r . 8
14 5.1.4 For ring cores of rectangular cross-section with appreciable chamfer c . 8
15 5.1.5 For ring cores of trapezoidal cross-section with sharp corners . 8
16 5.1.6 For ring cores of trapezoidal cross-section with an appreciable average
17 rounding radius r . 8
18 5.1.7 For ring cores of cross-section with circular arc frontal sides . 8
19 5.2 Pair of U-cores . 9
20 5.2.1 Pair of U-cores of rectangular section . 9
21 5.2.2 Pair of UR-cores . 9
22 5.2.3 Pair of URS-cores of rectangular-circular sections . 10
23 5.3 Pair of E-cores of rectangular section . 11
24 5.4 Pair of ETD/EER-cores . 12
25 5.5 Pair of pot-cores . 13
26 5.6 Pair of RM-cores . 16
27 5.7 Pair of EP-cores. 19
28 5.8 Pair of PM-cores . 21
29 5.9 Pair of EL-cores . 23
30 5.10 Pair of ER-cores (low profile) . 25
31 5.11 Pair of PQ-cores . 28
32 5.12 Pair of EFD-cores . 33
33 5.13 Pair of E planar-cores . 34
34 5.14 Pair of EC-cores . 37
36 Figure 1 – Ring cores . 7
37 Figure 2 – Pair of U-cores of the rectangular section . 9
38 Figure 3 – Pair of UR-cores of rounded section . 9
39 Figure 4 – Pair of URS-cores of rectangular-circular sections . 10
40 Figure 5 – Pair of E-cores of rectangular section . 11
41 Figure 6 – Pair of ETD/EER-cores . 12
42 Figure 7 – Pair of pot-cores . 14
43 Figure 8 – Pair of RM-cores . 17
44 Figure 9 – Pair of EP-cores . 20

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45 Figure 10 – Pair of PM-cores . 21
46 Figure 11 – Pair of EL-cores . 23
47 Figure 12 – PLT(plate)-cores . 23
48 Figure 13 – Pair of ER-cores (low profile) . 26
49 Figure 14 – PLT(plate)-cores . 26
50 Figure 15 – Pair of PQ-cores . 29
51 Figure 16 – PQ-cores . 30
52 Figure 17 – PLT(plate)-cores . 30
53 Figure 18 – Pair of EFD-cores . 33
54 Figure 19 – Pair of E planar-cores . 35
55 Figure 20 – PLT(plate)-cores . 35
56 Figure 21 – Pair of EC-cores . 37
IEC CDV 60205 © IEC 2024 4 51/1486/CDV

59 INTERNATIONAL ELECTROTECHNICAL COMMISSION
60 ____________
62 CALCULATION OF THE EFFECTIVE PARAMETERS
63 OF MAGNETIC PIECE PARTS
65 FOREWORD
66 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
67 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
68 international co-operation on all questions concerning standardization in the electrical and electronic fields. To
69 this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
70 Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
71 Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
72 in the subject dealt with may participate in this preparatory work. International, governmental and non-
73 governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
74 with the International Organization for Standardization (ISO) in accordance with conditions determined by
75 agreement between the two organizations.
76 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
77 consensus of opinion on the relevant subjects since each technical committee has representation from all
78 interested IEC National Committees.
79 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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83 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
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85 between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
86 the latter.
87 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
88 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
89 services carried out by independent certification bodies.
90 6) All users should ensure that they have the latest edition of this publication.
91 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
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94 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
95 Publications.
96 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
97 indispensable for the correct application of this publication.
98 9) IEC draws attention to the possibility that the implementation of this document may involve the use of a patent.
99 IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect
100 thereof. As of the date of publication of this document, IEC had not received notice of a patent, which may be
101 required to implement this document. However, implementers are cautioned that this may not represent the
102 latest information, which may be obtained from the patent database available at https://patents.iec.ch and/or
103 www.iso.org/patents. IEC shall not be held responsible for identifying any or all such patent rights.
104 International Standard IEC 60205 has been prepared by IEC technical committee 51:
105 Magnetic components, ferrite and magnetic powder materials.
106 This fifth edition cancels and replaces the fourth edition published in 2016. This edition
107 constitutes a technical revision.
108 This edition includes the following significant technical changes with respect to the previous
109 edition:
110 a) addition, in 5.2.3, of the drawing and the formulae of pair of URS-cores of rectangular-
111 circular section;
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112 b) using, in 5.9, 5.10, 5.11 and 5.13, of the conventional calculation formula that includes " B1-D " is
113 limited for the x-x cores (x is EL, ER, PQ or E) and addition new formulae for x-PLT cores that
114 replaces " B -D " with "(B -D+B )/2";
1 1 2
115 c) addition, in 5.9, 5.10, 5.11 and 5.13, of formulae of l1 and l3 for x-PLT cores (x is EL, ER,
116 PQ or E) which is different from the l and l of x-x cores;
1 3
117 d) addition of formula A in each subclause from 5.2.1 to 5.14.
min
119 The text of this standard is based on the following documents:
FDIS Report on voting
51/xxxx/FDIS 51/xxxx/RVD
121 Full information on the voting for its approval can be found in the report on voting indicated in
122 the above table.
123 The language used for the development of this International Standard is English.
124 This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
125 accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement,
126 available at www.iec.ch/members_experts/refdocs. The main document types developed by
127 IEC are described in greater detail at www.iec.ch/publications.
129 The committee has decided that the contents of this document will remain unchanged until the
130 stability date indicated on the IEC website under "webstore.iec.ch" in the data related to the
131 specific document. At this date, the document will be
132 • reconfirmed,
133 • withdrawn,
134 • replaced by a revised edition, or
135 • amended.
136 The contents of the corrigendum of July 2018 have been included in this copy.
IEC CDV 60205 © IEC 2024 6 51/1486/CDV

138 CALCULATION OF THE EFFECTIVE PARAMETERS
139 OF MAGNETIC PIECE PARTS
143 1 Scope
144 This document specifies uniform rules for the calculation of the effective parameters of closed
145 circuits of ferromagnetic material.
146 2 Normative references
147 There are no normative references in this document.
148 3 Terms and definitions
149 No terms and definitions are listed in this document.
150 ISO and IEC maintain terminological databases for use in standardization at the following
151 addresses:
152 • IEC Electropedia: available at http://www.electropedia.org/
153 • ISO Online browsing platform: available at http://www.iso.org/obp
154 4 Basic rules applicable to this standard
155 4.1 All results shall be expressed in units based on millimetres, shall be accurate to three
156 significant figures, but to derive l , A and V the values of C and C shall be calculated to
e e e 1 2
157 five significant figures. All angles are in radians.
158 NOTE The purpose of specifying this degree of accuracy is only to ensure that parameters calculated at different
159 establishments are identical and it is not intended to imply that the parameters are capable of being determined to
160 this accuracy.
161 4.2 A is the nominal value of the smallest cross-section. A is the geometrical cross-
min g
162 section of a ring core with rectangular shape. All the dimensions used to calculate A shall
min
163 be the mean values between the tolerance limits quoted on the appropriate piece part drawing.
164 All results shall be expressed in units based on millimetres and shall be accurate to three
165 significant figures.
166 NOTE A to be used for the measurement of the saturation flux density B on ring cores with rectangular cross-
g max
167 section.
168 4.3 Calculations are only applicable to the component parts of a closed magnetic circuit.
169 4.4 All dimensions used for the purpose of calculations shall be the mean value within the
170 tolerance limits quoted on the appropriate piece part drawing.
171 4.5 All irregularities in the outline of the core, such as small cut-outs, notches, chamfers,
172 etc. shall be ignored unless otherwise described.

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173 4.6 When the calculation involves the sharp corner of a piece part, then the mean length of
174 flux path for that corner shall be taken as the mean circular path joining the centres of area of
175 the two adjacent uniform sections, and the cross-sectional area associated with that length
176 shall be taken as the average area of the two adjacent uniform sections.
177 Calculation of effective parameters l , A and V .
e e e
178 The effective parameters can be defined as
2 3 2
179 l = C /C A = C / C V = l A = C / C
e 1 2 e 1 2 e e e 1 2
180 where
181 l is the effective magnetic length of the core (mm);
e
182 A is the effective cross-sectional area (mm );
e
183 V is the effective volume (mm );
e
−1
184 C is the core constant (mm );
−3
185 C is the core constant (mm ).
186 5 Formulae for the various types of cores
187 5.1 Ring cores
188 5.1.1 Ring cores in general
189 Drawings of ring cores are shown in Figure 1.
X
α
β
c0
r
r
4×
4×
r
ϕ
h
X h h h
X-X X-X X-X X-X
IEC
191 Figure 1 – Ring cores
2π
192 C =
h ln(d / d )
e 1 2
4π(1/ d − 1/ d )
2 1
193 C =
2 3
h ln (d / d )
e 1 2
d /2
d /2
c
d /2
d /2
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194 5.1.2 For ring cores of rectangular cross-section with sharp corners
195 h = h
e
196 The geometrical cross-section of a ring core with rectangular shape A is given as:
g
d − d
2 1
A = h
g
198 5.1.3 For ring cores of rectangular cross-section with an appreciable average
199 rounding radius r
200 h = h(1− k )
e 1
202 5.1.4 For ring cores of rectangular cross-section with appreciable chamfer c
4c
203 h = h(1− k ) k =
e 3 3
h(d − d )
1 2
204 The geometrical cross-section of a ring core with appreciable chamfer shape A is given as:
g
d − d
2 1 2
A = h − 2c
g 0
206 5.1.5 For ring cores of trapezoidal cross-section with sharp corners
( )
h tanα + tan β
207 h = h(1− k ) k =
e 2 2
d − d
1 2
208 5.1.6 For ring cores of trapezoidal cross-section with an appreciable average
209 rounding radius r
h = h(1− k − k )
e 1 2
211 5.1.7 For ring cores of cross-section with circular arc frontal sides
d − d  ϕ sinϕ ϕ 
1 2
h = h − 2sin − −
 
e
2 2 2
4 sin (ϕ / 2)  
d − d
1 2
ϕ = 2arcsin
4r
213 .
214 When the winding is uniformly distributed over a ring core, it may be expected that, at all
215 points inside the ring core, the flux lines will be parallel to its surface.
216 No leakage flux will therefore leave or enter the ring core. This justifies the use of a
217 theoretically more correct derivation of the effective parameters, which does not make use of
218 the assumption that the flux is uniformly distributed over the cross-section.

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219 5.2 Pair of U-cores
220 5.2.1 Pair of U-cores
...