oSIST prEN IEC 60404-3:2022

Magnetic materials - Part 3: Methods of measurement of the magnetic properties of electrical steel strip and sheet by means of a single sheet tester

Magnetni materiali - 3. del: Metode merjenja magnetnih lastnosti električnih jeklenih trakov in pločevine z uporabo enolistnega preskuševalnika

General Information

• Status: Not Published
• Public Enquiry End Date: 21-Apr-2022
• ICS: 17.220.20 - Measurement of electrical and magnetic quantities
• ICS: 29.030 - Magnetic materials
• Technical Committee: I11 - Imaginarni 11
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 04-Feb-2022
• Due Date: 24-Jun-2022
• Ref Project: prEN IEC 60404-3:2022 - Magnetic materials - Part 3: Methods of measurement of the magnetic properties of electrical steel strip and sheet by means of a single sheet tester

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN IEC 60404-3:2022
01-april-2022
Magnetni materiali - 3. del: Metode merjenja magnetnih lastnosti električnih
jeklenih trakov in pločevine z uporabo enolistnega preskuševalnika

Magnetic materials - Part 3: Methods of measurement of the magnetic properties of

electrical steel strip and sheet by means of a single sheet tester
Ta slovenski standard je istoveten z: prEN IEC 60404-3:2022
ICS:
17.220.20 Merjenje električnih in Measurement of electrical
magnetnih veličin and magnetic quantities
29.030 Magnetni materiali Magnetic materials
oSIST prEN IEC 60404-3:2022 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN IEC 60404-3:2022
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oSIST prEN IEC 60404-3:2022
68/699/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60404-3 ED3
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2022-01-28 2022-04-22
SUPERSEDES DOCUMENTS:
68/687/CD, 68/696/CC
IEC TC 68 : MAGNETIC ALLOYS AND STEELS
SECRETARIAT: SECRETARY:
Germany Mr Richard Daniel Knobloch
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

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.
TITLE:

Magnetic materials - Part 3: Methods of measurement of the magnetic properties of electrical steel strip

and sheet by means of a single sheet tester
PROPOSED STABILITY DATE: 2027
NOTE FROM TC/SC OFFICERS:

This Committee Draft for Vote was prepared by the responsible Project Leader and Team on the basis of the last

CD, 68/687CD, and the comments received from National Committees which are listed together with the

observations in 68/696/CC.

National Committees are invited to send their comments and vote on this document.

Copyright © 2022 International Electrotechnical Commission, IEC. All rights reserved. It is permitted to download 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.
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1 CONTENTS

2 FOREWORD ........................................................................................................................... 4

3 1 Scope ............................................................................................................................... 6

4 2 Normative references ....................................................................................................... 6

5 3 Terms and definitions 6

6 4 General principles of AC measurements ........................................................................... 7

7 4.1 General ................................................................................................................... 7

8 4.2 Principle of the Single Sheet Tester method ............................................................ 7

9 4.3 Test apparatus ........................................................................................................ 7

10 4.3.1 Yokes .......................................................................................................... 7

11 4.3.2 Windings ..................................................................................................... 9

12 4.4 Air flux compensation ............................................................................................ 10

13 4.5 Test specimen ....................................................................................................... 10

14 4.6 Power supply ………………………………………………………………………………….11

15 5 Determination of the specific total loss ........................................................................... 11

16 5.1 Principle of measurement ...................................................................................... 11

17 5.2 Apparatus ............................................................................................................. 11

18 5.2.1 Voltage measurement ................................................................................ 11

19 5.2.2 Frequency measurement ........................................................................... 12

20 5.2.3 Power measurement .................................................................................. 12

21 5.3 Measurement procedure of the specific total loss .................................................. 12

22 5.3.1 Preparation of measurement ..................................................................... 12

23 5.3.2 Adjustment of power supply ......................................................................... 12

24 5.3.3 Measurements ........................................................................................... 13

25 5.3.4 Reproducibility of the measurement of the specific totel loss ..................... 13

26 6 Determination of magnetic field strength, primary current and specific apparent power .. 14

27 6.1 General …………………………………………………………………………………………14
28 6.2 Principle of measurement ………………………………………………………………….…….14

29 6.2.1 Peak value of magnetic polarization .......................................................... 14

30 R.M.S. value of the primary current ........................................................... 14

6.2.2

31 6.2.3 Peak value of the magnetic field strength .................................................. 14

32 6.3 Apparatus ............................................................................................................. 15

33 6.3.1 Average type voltmeter .............................................................................. 15

34 6.3.2 Current measurement ................................................................................ 15

35 6.3.3 Peak current measurement ........................................................................ 15

36 Power supply ............................................................................................. 15

6.3.4

37 6.3.5 Resistor R ............................................................................................... 15

38 6.4 Measuring procedure ............................................................................................ 15

39 6.4.1 Preparation for measurement .................................................................... 15

40 Measurement ............................................................................................ 16

6.4.2

41 6.4.3 Non-oriented material ................................................................................ 16

42 6.5 Determination of characteristics ............................................................................ 16

43 6.5.1 Determination of Ĵ ..................................................................................... 16

44 6.5.2 Determination of H ..................................................................................... 17

45 6.5.3 Determination of H ..................................................................................... 17

46 6.5.4 Determination of S ................................................................................... 17

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47 6.5.5 Reproducibility of the measurement of the apparent power S

s ……………….18

48 7 Test Report .................................................................................................................... 18

49 Annex A (normative) Requirements concerning the manufacture of yokes ……………………..19

50 Annex B (informative) Check and verification of reliable performance of the SST- setup by the

51 use of reference samples and impact of the loss dissipated in the yokes ........................ 21

52 Annex C (informative) Epstein to SST relationship for grain-oriented sheet steel ................ 23

53 Annex D (informative) Digital sampling methods for the determination of the magnetic

54 properties and numerical air flux compensation .............................................................. 26

55 Bibliography........................................................................................................................ 30

56 Figure 1 – Schematic diagrammes of the test apparatus; Cross section of the SST (a) and

57 schematic view of the corner of a yoke with stacked lamination (b) ……………….….…………..8

58 Figure 2 – Yoke dimensions .................................................................................................... 9

59 Figure 3 – Diagram of the connections of the five coils of the primary winding ........................ 9

60 Figure 4 – Circuit for the determination of the specific total loss ........................................... 10

61 Figure 5 – Circuit for measuring the r.m.s. value of the primary current ................................ 14

62 Figure 6 – Circuit for measuring the peak value of the magnetic field strength ...................... 15

63 Figure B.1 - Specific loss vs. peak flux density (after J.Sievert [9] and F.Fiorillo [12]);

1.85
64 straight line: P ∝ J approximation (after C.Ragusa)…………………………………………… 21

66 Figure C.1 – SST-Epstein relative difference δP for grain-oriented material versus magnetic

67 polarization J ……………………………………………………………………………………………. 25

69 Figure C.2 – SST-Epstein rtelative difference δHS for grain-oriented material versus magnetic

70 polarization J……………………………………………………………………………………………….25

72 Table B.1 Loss dissipated in the yokes of an standard SST determined from the loss curves

73 measured on 3 yoke pairs as shown in Figure B.1, and relevant quantities including the

74 relative yokes’ contribution, p ; exemplified using 5 standard grades………………………….. 22

76 Table C.1 – SST-Epstein relative differences δP and δHS and the conversion factor FC for

77 (conventional) grain-oriented material in the polarization range 1,0 T to 1,8 T ………………. 24

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79 INTERNATIONAL ELECTROTECHNICAL COMMISSION
80 ____________
82 MAGNETIC MATERIALS –
84 Part 3: Methods of measurement of the magnetic properties
85 of electrical steel strip and sheet by means
86 of a single sheet tester
90 FOREWORD

91 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national

92 electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all

93 questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities,

94 IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications

95 (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees;

96 any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International,

97 governmental and non-governmental organizations liaising with the IEC also participate in this preparation. IEC

98 collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined

99 by agreement between the two organizations.

100 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus

101 of opinion on the relevant subjects since each technical committee has representation from all interested IEC National

102 Committees.

103 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees

104 in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate,

105 IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user.

106 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently

107 to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication

108 and the corresponding national or regional publication shall be clearly indicated in the latter.

109 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment

110 services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by

111 independent certification bodies.

112 6) All users should ensure that they have the latest edition of this publication.

113 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of

114 its technical committees and IEC National Committees for any personal injury, property damage or other damage of any

115 nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication,

116 use of, or reliance upon, this IEC Publication or any other IEC Publications.

117 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable

118 for the correct application of this publication.

119 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights.

120 IEC shall not be held responsible for identifying any or all such patent rights.

121 International Standard IEC 60404-3 has been prepared by IEC technical committee 68: Magnetic alloys

122 and steels.

123 This revised version of IEC 60404-3 was prepared on the basis of the consolidated edition 60404-3

124 Ed.2.2 which was modified introducing the following changes:

125 The text of the main part was revised, leaving the substantial technical contents unchanged;

126 Annex A forms an integral part of this standard. The method of determining the yokes’ lamination

127 resistance was added to Annex A.

128 Annex B of Ed.2.2 referred to calibration of the SST using the Epstein method. It was cancelled.

129 Annex B (new), C and D were revised, they are for information only.

130 Annex C was modified taking account of the new situation regarding P and R grades.

131 Annex D was amended by addition of sub-clause D.4 on the numerical air flux compensation

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132 The committee has decided that the contents of the base publication and its amendments will remain

133 unchanged until the maintenance result date indicated on the IEC web site under

134 "http://webstore.iec.ch" in the data related to the specific publication. At this date, the publication will

135 be
136 • reconfirmed,
137 • withdrawn,
138 • replaced by a revised edition, or
139 • amended.
140
141
142
143
144
145
146
147
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148 MAGNETIC MATERIALS –
149
150 Part 3: Methods of measurement of the magnetic properties
151 of electrical steel strip and sheet by means
152 of a single sheet tester
153
154
155
156 1 Scope

157 This part of IEC 60404 is applicable to grain-oriented and non-oriented electrical steel strip and sheet

158 for measurement of AC magnetic properties at power frequencies.
159

160 The object of this document is to define the general principles and the technical details of the

161 measurement of the magnetic properties of electrical steel strip and sheet by means of a single sheet

162 tester (SST).

163 The single sheet tester is applicable to test specimens obtained from electrical strips and sheets of

164 any grade. The AC magnetic characteristics are determined for sinusoidal induced voltages, for

165 specified peak values of the magnetic polarization, for specific peak values of the magnetic field

166 strength and for a specified frequency.

167 The measurements are made at an ambient temperature of 23 °C ± 5 °C on test specimens which have

168 first been demagnetized.

169 NOTE Throughout this part the quantity "magnetic polarization" is used as defined in IEC 60050-221. In some standards of

170 the IEC 60404 series, the quantity "magnetic flux density" was used.
171
172 2 Normative references

173 The following documents are referred to in the text in such a way that some or all of their content

174 constitutes requirements of this document. For dated references, only the edition cited applies. For

175 undated references, the latest edition of the referenced document (including any amendments) applies.

176 IEC 60050-121, International Electrotechnical Vocabulary – Part 121: Electromagnetism

177 IEC 60050-221, International Electrotechnical Vocabulary – Part 221: Magnetic materials and

178 components

179 IEC 60404-13, Magnetic materials – Part 13: Methods of measurement of resistivity, density and

180 stacking factor of electrical steel strip and sheet
181 3 Terms and definitions

182 For the purposes of this document, the terms and definitions given in IEC 60050-121 and IEC 60050-

183 221 apply.

184 ISO and IEC maintain terminological databases for use in standardization at the following addresses:

185  IEC Electropedia: available at http://www.electropedia.org/
186  ISO Online browsing platform: available at http:www.iso.org/obp
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187 4 General principles of AC measurements
188 4.1 General

189 Clause 4 specifies the general conditions for the determination of AC magnetic properties of electrical

190 steel strip and sheet at power frequencies by means of a single sheet tester.

191 4.2 Principle of the single sheet tester method

192 The test specimen comprises a sample of electrical steel sheet and is placed in the center of two

193 concentric windings:
194 – an exterior primary winding (magnetizing winding);
195 – an interior secondary winding (voltage winding).

196 The flux closure is made by a magnetic circuit consisting of two identical yokes, the cross-section of

197 which is very large compared with that of the test specimen (see Figure 1).

198 Care shall be taken to ensure that the temperature changes of the specimen are kept below a level

199 likely to produce stress in the test specimen due to thermal expansion or contraction.

200 4.3 Test apparatus
201 4.3.1 Yokes

202 Each yoke is in the form of a U made up of insulated sheets of grain-oriented electrical steel. It shall

203 have a low reluctance and a low specific total loss in the low magnetic polarization region below 0,1 T.

204 (see Annex A). It shall be manufactured in accordance with the requirements of Annex A.

205 In order to reduce the effect of eddy currents and give a more homogeneous distribution of the flux

206 over the inside of the yokes, the latter shall be made of a pair of wound cut C-cores or a glued stack

207 of laminations in which case the corners shall have staggered butt joints (see Figure 1).

208 The yoke shall have pole faces having a width of 25 mm ± 1 mm.

209 The two pole faces of each yoke shall be coplanar to within 0,5 mm and the gap between the opposite

210 pole faces of the yokes shall not exceed 0,005 mm at any point. Also, the yokes shall be rigid in order

211 to avoid creating mechanical stresses in the test specimen.

212 The height of each yoke shall be between 90 mm and 150 mm. Each yoke shall have a width of 500

213 mm and an inside length of 450 mm ± 1 mm (see Figure 2).

214 There shall be a non-conducting, non-magnetic support on which the test specimen is placed, between

215 the vertical limbs of the bottom yokes. This support shall be centered and located in the same plane

216 as the bottom yoke pole faces so that the test specimen is in direct contact with the pole faces without

217 any gap. Care shall be taken that in no case the upper surface of the support is positioned higher than

218 the plane of the pole faces of the bottom yoke.
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219
220 (a)
221
222 (b)
223

224 Figure 1 – Schematic diagrammes of the test apparatus; Cross section of the SST (a) and

225 schematic view of the corner of a yoke with stacked lamination (b)

226 The upper yoke shall be movable upwards to permit insertion of the test specimen. After insertion of

227 the test specimen the upper yoke shall be lowered to close the magnetic circuit and, simultaneously,

228 the pole faces of the bottom and upper yokes shall be aligned accurately. To minimize the effects of

229 pressure on the test specimen, the upper yoke shall be provided with a means of suspension. The

230 suspension of the upper yoke shall allow part of its weight to be counterbalanced so as to give a force

231 on the test specimen of between 100 N and 200 N.

232 NOTE The square configuration of the yoke has been chosen in order to have only one test specimen for non-oriented

233 material. By rotating the test specimen through 90° it is possible to determine the characteristics in the rolling direction and

234 perpendicular to the rolling direction.
235
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236
237 Figure 2 – Yoke dimensions
238
239 4.3.2 Windings
240 The coil system inside the yokes shall have two windings:
241 – a primary winding, on the outside (magnetizing winding);
242 – a secondary winding, on the inside (voltage winding);

243 The primary (outer) and secondary (inner) windings shall be at least 440 mm in length and shall

244 be wound uniformly on a non-conducting, non-magnetic and rectangular former. The dimensions of

245 the former shall be as follows:
246 – length: 445 mm ± 2 mm;
247 – internal width: 510 mm ± 1 mm;
0
248 mm;
– internal height: 5
249 – height: ≤15 mm.
250 The primary winding can be made up of:

251 – either five or more coils having identical dimensions and the same number of turns connected in

252 parallel and taking up the whole length (see Figure 3). For example, with five coils, each coil can

253 be made up of 400 turns of copper wire 1 mm in diameter, wound in five layers;

254 – or a single continuous and uniform winding taking up the whole length. For example this winding

255 can be made up of 400 turns of copper wire 1 mm in diameter, wound in one layer.

256

257 Figure 3 – Diagram of the connections of the five coils of the primary winding

258
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259 The number of turns on the secondary winding will depend on the characteristics of the measuring

260 instruments. In any case, the determination of the number of turns of the primary and secondary

261 windings shall be made with greatest reliability because a mistake would mean a permanent error.

262 4.4 Air flux compensation

263 Compensation shall be made for the effect of air flux. This can be achieved, for example, by a mutual

264 inductor M (see Figure 4). The primary winding of the mutual inductor is connected in series with the

265 primary winding of the test apparatus, while the secondary winding of the mutual inductor is connected

266 to the secondary winding of the test apparatus in series opposition.
267
268 Key
269 V1 measures the average rectified voltage
270 V2 measures the r.m.s. voltage
271 A measures the r.m.s. value of the primary current
272 Hz measures the frequency
273 W measures the power
274 M is the mutual inductor
275 T is the test frame
276
277 Figure 4 – Circuit for the determination of the specific total loss
278

279 The adjustment of the value of the mutual inductance shall be made so that when passing an alternating

280 current through the primary windings in the absence of the test specimen in the test apparatus, the

281 voltage measured between the non-common terminals of the secondary windings shall be no more than

282 0,1 % of the voltage appearing across the secondary winding of the test apparatus alone. Thus the

283 average value of the rectified voltage induced in the combined secondary windings is proportional to

284 the peak value of the magnetic polarization in the test specimen.

285 NOTE 1 Alternatively, the air flux compensation can be executed by the numerical method (for details see Annex D,

286 Clause D.4).

287 NOTE 2 In the rest of this document the term “compensated secondary voltage” is used to mean “voltage induced in the

288 secondary winding compensated for the effect of air flux”.
289
290 4.5 Test specimen

291 The length of the test specimen shall be not less than 500 mm. Although the part of the test specimen

292 situated outside the pole faces has no great influence on the measurement, this part shall not be longer

293 than is necessary to facilitate insertion and removal of the test specimen.

294 The width of the test specimen shall be as large as possible and at its maximum equal to the width of

295 the yokes.
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296 For optimum accuracy, the minimum width shall be not less than 60 % of the width of the yokes.

297 NOTE 1 Specific restrictions of the dimensions of the test specimens can be defined for special material grades in the

298 respective product standards for magnetic materials.
299

300 NOTE 2 Information about application of the SST to strip samples of 50 mm to 250 mm width: Grain-oriented electrical steel

301 used for distribution transformer (DT) cores is merchandized in the form of slit coils of 50 mm to 250 mm width cut from the

302 as produced steel strips (master coils) at the different positions across the original strips. The slit coils reflect the

303 considerable variation of the material properties corresponding to the position on the original strip, where they have been

304 cut from. These small strip specimens can be measured using this SST placing them side by side or with distributed gaps in

305 the SST. In order to attain a relevant measurement result a minimum of 60 % of the 500 mm wide sample space needs to be

306 filled with strips. The test strip samples may be taken successively from the start or the end of a slit coil. When preparing

307 them taking care would avoid any damage which could influence the test result. Due to the cutting of the sheet into the small

308 strips, the measured loss of narrow strips will be slightly increased compared to the original 500 mm.

309

310 The test specimen shall be cut without the formation of excessive burrs or mechanical distortion. The

311 test specimen shall be plane. When a test specimen is cut, the edge of the parent strip is taken as

312 the reference direction. The angle between the direction of rolling and that of cutting shall not

313 exceed:
314 ±1° for grain oriented steel sheet;
315 ±5° for non-oriented steel sheet.

316 For non-oriented steel sheet, two specimens shall be cut, one parallel to the direction of rolling and the

317 other perpendicular unless the test specimen is square, in which case one test specimen only is

318 necessary.
319 4.6 Power supply

320 The power supply shall be of low internal impedance and shall be highly stable in terms of voltage and

321 frequency. During the measurement, the voltage and the frequency shall be maintained constant within

322 ±0,2 %.

323 In addition, the waveform of the compensated secondary voltage shall be maintained as sinusoidal as

324 possible. The form factor of the compensated secondary voltage shall be maintained to within ±1 % of

325 1,111. This can be achieved by various means, for example by using an electronic feedback amplifier

326 or by a computational digital feedback system.
327 5 Determinat
...