1、UDC 621.318.1 : 621.317.4 : 001.4 DEUTSCHE NORM August i9aa Determination of magnetic properties of soft magnetic materials General, terminology and principles of measurement DIN 50 460 Bestimmung der magnetischen Eigenschaften von weichmagnetischen Werk- stoffen; Allgemeines, Begriffe, Grundlagen d
2、er Prfverfahren Supersedes September 1980 edition of this standard and September 1975 edition of DIN 50465. In keeping with current practice in standards published by the International Organization for Standardization (/SO), a comma has been used throughout as the decimal marker. 1 Field of applicat
3、ion . 2 Scope . 2.1 d.c. magnetic field quantities 2.2 a.c. magnetic field quantities . 3 Terminology . 3.1 Test volume 3.2 Effective specimen mass 3.3 Specimen cross-sectional area. 3.4 Magnetic circuit . 3.5 Effective magnetic path length in a closed circuit . 3.6 3.7 Flux sensing winding (seconda
4、ry winding) Magnetizing winding (primary winding) . Contents . 2 7.2 Determination of magnetic field strength . 8 . 2 7.2.1 Determination of field strength . 2 from the closed-circuit magnetizing current. 8 sensing coils 8 Page Page , . , 2 . . 7.2.3 Direct measurement of field strength using 2 2 2
5、2 7.2.2 Measurement of field strength using field . field sensing probes 8 from the open-circuit magnetizing current with no closure yoke 9 . 2 7.3.1 Demagnetizing the specimen . 9 . 2 7.3.2 Measurement procedure . 9 . . 7.2.4 Determination of field strength . . . . 2 7.3 Plotting a normal magnetiza
6、tion curve 9 3.8 Field sensing coils and probes 3 3.9 Induced voltage (secondary voltage) 3 4 Quantities, symbols and unlts 3 5 Basic measurement requirements 5 6 Magnetic circuits 5 6.1 Closed circuits consisting of specimen material only . 5 6.2 Circuits including a closure yoke 5 6.3 Open circuit
7、s 5 6.4 User information . 5 7 d.c. magnetic fidd measurement methods. . 5 7.1 Determination of flux density . 5 7.1.1 Closed-circuit measurement of flux density 5 7.1.1.1 Air flux compensation. 5 7.1.1.2 Determination of fluxmeter constant . 6 7.1.1.3 Measurement with rapid changes in flux 6 7.1.1.
8、4 Measurement with slow changes in flux 6 7.1.2 Open-circuit measurement of flux density with no closure yoke . 6 7.1.2.1 Determination of polarization with large distance of measurement . 7 7.1.2.2 Determination of polarization with small distance of measurement . 7 7.1.2.3 Determination of flux de
9、nsity by the induction method using a fixed specimen and flux sensing winding 7 7.1.2.4 Determination of flux density or polarization by the withdrawal method . 8 7.4 Relative permeability., 10 7.5 Plotting a hysteresis loop 10 7.5.1 Plotting a closed-circuit hysteresis loop . 10 7.5.2 Plotting an o
10、pen-circuit hysteresis loop. 11 7.5.3 Continuous plotting of a hysteresis loop 11 7.6 Hysteresis energy loss per cycle. 12 7.7 Remanent flux density or remanent polarization. 12 7.7.1 Determination from the hysteresis loop . 12 7.7.2 Closed-circuit determination . 12 7.8 Coercivity 12 7.8.1 Determin
11、ation from the hysteresis loop . 12 7.8.2 Open-circuit measurement of polarization coercivity. 12 7.8.2.1 Measuring arrangement using compensating coil . 13 7.8.2.2 Measuring arrangement using probes for measuring radial field components 13 7.8.2.3 Measuring arrangement using a vibrating search coil
12、 13 7.8.2.4 Calibration of measuring arrangements for open-circuit measurement of coercivity . 13 8 a.c. magnetic field measurement methods . 14 8.1 Determination of flux density 14 8.1.1 Instantaneous values of flux density 14 8.1.2 Peak flux density 14 8.1.3 Form factor of induced voltage . 14 8.1
13、.4 Air flux compensation . 14 Continued on pages 2 to 20 uth Verlag GmbH. Beriin, has the exclusive right 01 sale for German Standards (DIN-Normen). DIN 50460 Engl. Price group i 05.90 Sales No. O1 13 Page 2 DIN 50460 Page 8.2 Determination of magnetic field strength . 15 8.2.1 Determination of fiel
14、d strength from magnetizing current . 15 8.2.2 Measurement of field strength using field sensing coils 15 8.2.3 Other methods of measuring field strength 15 8.2.4 Instantaneous value of field strength . 15 8.2.4.1 Determination from magnetizing current 15 8.2.4.2 Measurement using a field sensing co
15、il 16 8.2.5 Peak field strength 16 8.2.5.1 Determination from magnetizing current 16 8.2.5.2 Measurement using a field sensing coil 16 8.2.6 r.m.s value of field strength 16 8.2.6.1 Determination from magnetizing current 16 8.2.6.2 Measurement using a field sensing coil 16 8.3 Determination of a.c.
16、magnetization curve and amplitude permeability 16 8.4 Dynamic hysteresis loop . 17 8.4.1 Determination using phase-controlled rectifiers 17 1 Field of application This standard applies to measurements made with the specimen either in a d.c.magnetic field or in an a.c. magnetic field without a d.c. c
17、omponent with frequencies from 15 to 400 Hz and with a sinusoidalvariation in flux densityor pola- rization. 2 Scope This standard is intended to describe the principles of determining the magnetic properties of soft magnetic materials, to define the concepts used and to specify the requirements rel
18、ating to the methods of measurement. The quantities covered are the following. 2.1 d.c. magnetic field quantities Maximum magnetic flux density, Bmax, or maximum magnetic polarization, Jmm, as a function of the maxi- mum magnetic field strength,Hmax (normal magnetiza- tion curve), Bm,=f(Hmm) or Jmax
19、=f(Hmax); relative permeability, pr = f(HmaX); pairs of values B and H orJ and H required to plot the hysteresis loop; hysteresis energy loss, W, = f(Bmm) or W, = f(JmaX); remanent flux density or remanent polarization, coercivity, HB =f(B B=f(H) orJ=f(H); relative-a.c. field magnetic permeability,
20、pr= f(l?) or pairs ofvalues B(t) and H(t) orJ(t) and H(t) for plotting the dynamic hysteresis loop; remanent fux density or polarization, Br =Ir =f(B) or coercivity, Hc = f(6) or HCj =ru); Pa = f (H); Br =Ir = f U); Page 8.4.2 Determination using an oscilloscope. . 17 8.5 Remanent flux density or re
21、manent polarization 17 8.5.1 Determination from a point-by-point plot of the dynamic hysteresis loop . 17 8.5.2 Determination using an oscilloscope. . 17 8.6.1 Determination from a point-by-point plot of the dynamic hysteresis loop . 17 8.6.2 Determination using an oscilloscope. . 17 8.7 Determinati
22、on of specific total loss . 17 8.7.1 Wattmeter method. . 17 8.7.1.1 Determination from the magnetizing current. 18 8.7.1.2 Determination using field sensing coils 18 8.7.2 Loop area method . 19 8.7.4 Breakdown of losses 19 8.8 Determination of specific apparent power 19 8.4.3 Digital measurement met
23、hods 17 8.6 Coercivity 17 8.7.3 Digital method 19 f) specific total loss (total power loss), ,=f(i) or P,=fV); g) specific apparent power, S, = f(i) or s,= fe). 3 Terminology 3.1 Test volume The test volume, V, is that part of the specimen volume which is involved in the measurement. 3.2 Effective s
24、pecimen mass The effective specimen mass, ma, is the mass of that part of the specimen in which the total power losses occur. 3.3 Specimen cross-sectional area The cross-sectional area of a specimen, A, is its area at the point of measurement through which the flux passes. 3.4 Magnetic circuit The m
25、agnetic circuit is a closed path through which the magnetic flux generated by the current in the magnetizing winding passes. 3.5 Effective magnetic path length The effective magnetic path length, ,.is equal to the length of a straight, uniformly magnetized equivalent magnetic conductor having consta
26、nt cross section across which the drop in the magnetomotive force produced bythe electrical excitation is the same as in a closed circuit.with the same field strength. in a closed circuit 3.6 Magnetizing winding (primary winding) The magnetizing winding serves to magnetize the speci- men. In the cas
27、e of transformer-type assemblies, the mag- netizing winding is also termed primary winding. 3.7 Flux sensing winding (secondary winding) The flux sensing winding surrounds the test volume and serves to determine the flux density or the polarization in the specimen. It encloses the magnetic flux in t
28、he speci- men cross section and in the air gap between the winding and the specimen. In the case of transformer-type assem- blies, the flux sensing winding is also termed secondary winding.The individual turns of the winding are normal to the specimen axis. DIN 50460 Page 3 Quantity Axial component
29、of magnetic fieid strength at position of field sensing probe 1 Axial component of magnetic field strength at position of field sensing probe 2 Peak value of magnetic field strength (a.c. magnetic field) r.m.s. value of magnetic field strength 3.8 Field sensing coils and probes Field sensing coils a
30、nd field sensing probes serve to meas- ure the field strength close to the specimen surface or, if the specimens consist of several parts, at points between the parts at which the field strength can be regarded as being approximately equal to the field strength inside the specimen. 3.9 Induced volta
31、ge (secondary voltage) The induced voltage (secondary voltage) is generated by the change in total flux in the flux sensing winding. 4 Quantities, symbols and units Table 1 summarizes the quantities, symbols and units used in this standard. Table 1. Unit AJm Alm Al m Alm Symbol B B, Magnetic flux de
32、nsity T Maximum magnetic flux density T Hz 2 H H H External magnetic field strength I Alm Symbol Quantity Unit 1 Alm Magnetic field strength at peak magnetic flux density A Magnetic field strength at peak magnetic polarization Total turn area of flux sensing coil Il Magnetizing current m2, mm2 Cross
33、-sectional area of flux sensing winding il r.m.s. value of magnetizing current Half diameter of I ellipsoid of revolution a il A Instantaneous value of magnetizing current Current due to inductance M, in primary winding A Magnetic polarization T T Maximum magnetic polarization (in d.c. magnetic fiel
34、d) I“ Instantaneous value of magnetic flux density at time tl Remanent flux density J B1 Br i T Peak value of magnetic flux density - b Imax JI Remanent polarization IT 12 Half length of ellipsoid I of revolution Magnetic polarization in axial direction i dl Peak value of magnetic polarization (in a
35、.c. magnetic field) Outside diameter of a ring specimen Inside diameter of a ring specimen Form factor of induced voltage i d2 Sum index in equations (61) and (62) k F Fluxmeter constant Fluxmeter constant for flux density determination I HZ f I Frequency H I Magnetic field strength I Alm I Wb Fluxm
36、eter constant for field strength determination I Alm Instantaneous value of magnetic field strength at time tl “ I 1 Length of test strip or of solenoid 1 m Im Effective path length of magnetic circuit Mutual inductance for air flux Mutual inductance for determining instantaneous magnetic current Ma
37、ximum magnetic field strength of hysteresis loop (in d.c. magnetic field) 1 Alm Axial component of stray field HZ I strength l) 1 represents a dimensionless quantity. Page 4 DIN 50 460 Table 1 (concluded). Symbol Quantity Unit Symbol I Quantity Unit Half-wave average of voltage across field sensing
38、coil V Precision mutual inductance for fluxmeter calibration Mn I H Instantaneous value of induced voltage V ma I Effective specimen mass V N I Demagnetization factor Instantaneous value of secondary voltage of MD Instantaneous value of voltage induced in field sensing coils UD Number of turns of ma
39、gnetizing winding Number of turns of flux sensing N2 winding Number of turns per unit length of solenoid n V Un Instantaneous value of voltage across resistor R, V 1 Im Instantaneous value of voltage at output of integrator V Number of points per cycle in equations (61) and (62) I n Vrn Test volume
40、m3 Calculated total power loss of specimen I W W Hysteresis energy loss ws Wlkg Wslkg Eddy current loss Hysteresis loss Measured power (indicated on wattmeter) Specific hysteresis energy loss per cycle Distance on axis from centre of ellipsoid of revolution or distance between a point on the axis fr
41、om end of solenoid Wlkg W 2 m Ph I Measured power loss w a Analogue indication of fluxmeter Specific total loss (total power loss) of specimen I Wlkg Indication of fluxmeter in flux density determination Indication of fluxmeter in field strength determination p I Half-axis ratio of ellipsoid a Sum o
42、f instrument resistances in flux sensing circuit Q Indication of fluxmeter during calibration Value of measuring resistor in magnetizing current circuit Input voltageloutput current ratio of voltage-current converter Variable resistor Additional variable resistor Q Pa Amplitude permeability Hlm Magn
43、etic field constant =4 x 10- Rs 1 Q PO Rs 2 a PI 11) kglm3 Permeability Density of specimen material Total resistance of flux sensing winding and secondary winding I ofMc Q 5i Time constant of integrator S Radius of sphere or of I single-layer solenoid r m Air flux Flux through specimen Wb Wb VAlkg
44、Specific apparent power Cycle duration = llf r.m.s. value of induced voltage Half-wave average of induced voltage Return flux through space between ellipsoid of revolution and flux sensing coil S V cos (p Power factor V Xrn Relative magnetic susceptibility V Half-wave average of secondary voltage ac
45、ross MD 1) 1 represents a dimensionless quantity. DIN 50460 Page 5 5 Basic measurement requirements 5.1 The magnetic properties of the specimen in the test volume shall be representative of the sample. 5.2 The flux density in, or the polarization of, the test volume shall be as uniform as possible.
46、5.3 Fora.c.magnetic field measurements.thevariation of the flux density or the polarization with time shall be made sinusoidal by providing for the impedance of the primary circuit (without the specimen in place) to be as low as pos- sible. If the induced voltage is still distorted, the sinusoidal f
47、orm shall be provided by using an adjusting loop.This is to be checked by determining the form factor of the induced voltage; this factor shall not deviate from 1.111 by more than +1%. 5.4 The form factor, frequency, power, voltage, current, voltage time integrals and geometrical data shall be meas-
48、 ured to ensure that the uncertainties of measurement results are kept within the specified limits. 5.5 Measurement sha! be perfoImed using specified ref- erence quantities (e.g. B= 1,5T, H =500Aim). 6 Magnetic circuits 6.1 Closed circuits consisting of specimen material only 6.1.1 Magnetic circuits
49、 are formed by ring specimens con- sisting of a strip wound toroidal core, a stack of annular laminations or a ring machined from solid material, or 6.1.2 rectangular specimens (in general, polygonal speci- mens) made up of cut strips assembled so as to form a rec- tangle (polygon), ag. specimens for the 25cm Epstein frame as specified in DIN 50462 Part 1, or specimens of solid material. 6.2 Circuits including a closure yoke Closure yokes are used for slit strip, sheet, strip and rod specimens, single strip tester, single sheet tester and per- meameter being customary yoke ty
