BS EN 60375-2004 Conventions concerning electric and magnetic circuits《关于电路和磁路的规定》.pdf

1、BRITISH STANDARD BS EN 60375:2003 Conventions concerning electric and magnetic circuits The European Standard EN 60375:2003 has the status of a British Standard ICS 17.220.01 BS EN 60375:2003 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 6

2、April 2004 BSI 6 April 2004 ISBN 0 580 43579 2 National foreword This British Standard is the official English language version of EN 60375:2003. It is identical with EN 60375:2003. The UK participation in its preparation was entrusted to Technical Committee SS/7, General metrology, quantities, unit

3、s and symbols, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalo

4、gue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its corr

5、ect application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor

6、 related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 20, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when t

7、he document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 60375 NORME EUROPENNE EUROPISCHE NORM September 2003 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elek

8、trotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2003 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60375:2003 E ICS 17.220.01 English version Conventions concerning electric and magnetic circuits

9、 (IEC 60375:2003) Conventions concernant les circuits lectriques et magntiques (CEI 60375:2003) Vereinbarungen fr Stromkreise und magnetische Kreise (IEC 60375:2003) This European Standard was approved by CENELEC on 2003-09-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regula

10、tions which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This

11、 European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members

12、 are the national electrotechnical committees of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Lithuania, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom. EN 60375:2003 - 2 - Fo

13、reword The text of document 25/261/FDIS, future edition 2 of IEC 60375, prepared by IEC TC 25, Quantities and units, and their letter symbols, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60375 on 2003-09-01. The following dates were fixed: latest date by which th

14、e EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2004-06-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2006-09-01 Annexes designated “normative“ are part of the body of the standa

15、rd. In this standard, annex ZA is normative. Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 60375:2003 was approved by CENELEC as a European Standard without any modification. _ Page2 EN60375:200360375 IEC:2003 3 CONTENTS OFREWODR 5 1 Scope 4 2 No

16、rmative references. 4 3 Terms and definitions 4 4 Direction rules for current 6 4.1 Physical direction of current.6 4.2 Reference direction of current6 4.3 Indication of the reference direction for currents 6 4.4 Kirchhoff law for nodes 7 5 Polarity rules 8 5.1 Voltage8 5.2 Reference polarity for a

17、pair of nodes 8 5.3 Indication of the reference polarity.8 5.4 Kirchhoff law for meshes10 6 Conventions concerning two-terminal passive networks10 6.1 General conventions10 6.2 Resistive element 10 6.3 Inductive element 11 6.4 Capacitive element 11 6.5 Non-ideal two-terminal circuit elements .11 7 C

18、onventions for two-port networks12 8 Conventions concerning sources 12 8.1 Conventions concerning voltage sources .12 8.2 Conventions concerning current sources .13 9 Conventions concerning magnetic circuits.14 9.1 Magnetic flux .14 9.2 Linked flux.15 9.3 Conventions concerning mutual inductance .15

19、 10 Complex notation16 10.1 Conventions concerning complex representation of sinusoidal quantities.16 10.2 Reference direction of a complex current.17 10.3 Reference polarity for a complex voltage .17 10.4 Complex representation of Ohms law18 10.5 Conventions concerning the graphical representation

20、of phasors.19 10.6 Conventions concerning phase differences19 Page3 EN60375:2003 Annex ZA (normative) Normative references to international publications with their corresponding European publications . 2060375 IEC:2003 7 CONVENTIONS CONCERNING ELECTRIC AND MAGNETIC CIRCUITS 1 Scope This Internationa

21、l Standard lays down rules for signs and reference directions and reference polarities for electric currents and voltages in electric networks, as well as for the corresponding quantities in magnetic circuits. In Clauses 3 to 9, the time dependence is arbitrary. Clause 10 details the rules and recom

22、- mendations for complex notation. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments)

23、applies. IEC 60050-121:1998, International Electrotechnical Vocabulary (IEV) Part 121: Electro- magnetism IEC 60050-131:2002, International Electrotechnical Vocabulary (IEV) Part 131: Circuit theory IEC 60617, Graphical symbols for diagrams 3 Terms and definitions For the purposes of this document,

24、the following terms and definitions apply. 3.1 terminal point of interconnection of an electric circuit element, an electric circuit or a network (IEC 60050-131:2002, 131-13-03) with other electric circuit elements, electric circuits or networks IEV-131-11-11 NOTE 1 For an electric circuit element,

25、the terminals are the points at which or between which the related integral quantities are defined. At each terminal, there is only one electric current from outside into the element. NOTE 2 The term “terminal” has a related meaning in IEC 60050-151. 3.2 circuit element in electromagnetism, mathemat

26、ical model of a device characterized by one or more relations between integral quantities IEV-131-11-03 Page4 EN60375:200360375 IEC:2003 9 3.3 two-terminal element electric circuit element having two terminals IEV 131-11-16 3.4 n-terminal circuit element electric circuit element having n terminals w

27、ith generally n 2 IEV-131-11-13 NOTE For an n-terminal electric circuit element: 1) the algebraic sum of the electric currents into the element through the terminals is zero at any instant; 2) there are n 1 independent relations between integral quantities. 3.5 network in network topology, set of id

28、eal circuit elements and their interconnections, considered as a whole IEV-131-13-03 NOTE 1 The term “electric network” is defined in IEC 60050-131-11-07 and in IEC 60050-151. NOTE 2 In diagrams in this standard, a box, IEC 60617 symbol, represents any network, unless otherwise specified. 3.6 branch

29、 subset of a network, considered as a two-terminal circuit, consisting of a circuit element or a combination of circuit elements IEV-131-13-06 3.7 node, vertex (US) end-point of a branch connected or not to one or more other branches IEV-131-13-07 3.8 loop closed path passing only once through any n

30、ode IEV-131-13-12 3.9 tree connected set of branches joining all the nodes of a network without forming a loop IEV-131-13-13 3.10 co-tree set of the branches of a network not included in a chosen tree IEV-131-13-14 Page5 EN60375:200360375 IEC:2003 11 3.11 link branch of a co-tree IEV-131-13-15 3.12

31、mesh set of branches forming a loop and containing only one link of a given co-tree IEV-131-13-16 Remark: The English terms voltage, electric potential difference, and electric tension have the same meaning in the area of electric circuits. In the English language version of the IEV voltage is the p

32、referred term and electric tension, often shortened to tension, is an alternative. This standard uses the term voltage. The term electric current is often shortened to current according to IEC 60050-121. For electric networks with lumped circuit elements (see IEC 60050-131), the Kirchhoff law for no

33、des (see 4.4) applies for the quantity current, and the Kirchhoff law for meshes (see 5.4) applies for the quantity voltage. 4 Direction rules for current 4.1 Physical direction of current The net flow of electric charge through a surface is referred to as electric current. By convention, the physic

34、al direction of the current i is defined as the direction corresponding to the movement of positive charge. If the quasi-infinitesimal charge dq passes through a predetermined surface, for example the cross-section of a conductor, during the duration dt, the electric current is t q i d d = 4.2 Refer

35、ence direction of current The reference direction for the current in a branch or in a mesh is a direction fixed arbitrarily along the branch or around the mesh. A current is considered as positive when its physical direction corresponds to the reference direction. 4.3 Indication of the reference dir

36、ection for currents 4.3.1 Indication of the reference direction for currents for a branch An arrow having the direction corresponding to the reference direction for a current is placed on or near the line representing the branch element, or near the branch element. (See Figure 1.) The notations in F

37、igures 1a and 1b are preferred. Figure 1a Figure 1c Figure 1b Figure 1d Figure 1 Indication of the reference direction for a current by an arrow Page6 EN60375:200360375 IEC:2003 13 When there is only one branch between two nodes, it is clearer to use the notations for the nodes (a and b in Figure 2)

38、 to denote the direction of the current, in this case i ab , which defines a current directed from a to b in a branch ab. It is useful to combine consistently the indication by an arrow and by using node designations as in Figure 2. The notations in Figures 2a and 2b are preferred.Figure 2a Figure 2

39、b Figure 2c Figure 2d ab ab ab ab a Figure 2 Indication of the reference direction for a current using the node names 4.3.2 Indication of the reference direction for mesh currents To indicate in a diagram the reference direction for the current around a mesh, a curved arrow having a corresponding di

40、rection is placed in the mesh so as to follow its contour. In Figure 3, an example shows the connection between mesh currents and branch currents. a Figure 3 Indication of the reference direction for mesh currents 4.4 Kirchhoff law for nodes The Kirchhoff law for nodes states: The algebraic sum of t

41、he branch currents towards any node of an electric network is zero (see IEC 60050-131:2002, 131-15-09). According to the currents defined in Figure 4a, this means that the Kirchhoff law for nodes applied to node e reads 0 de ce be ae = + + + i i i i If the reference direction of a current, for examp

42、le the current in branch between b and e in Figure 4b, is chosen as away from the node e, the corresponding current ii eb be = = = = , shall be taken with the opposite sign. In that case, the Kirchhoff law for nodes states: 0 de ce eb ae = + + i i i i Page7 EN60375:200360375 IEC:2003 15 Figure 4a Fi

43、gure 4b Figure 4 Examples of the Kirchhoff law for nodes 5 Polarity rules for voltage 5.1 Voltage In an electric network, a voltage between two ordered nodes, a and b, is the difference of the electric potentials at node a and node b. 5.2 Reference polarity for a pair of nodes The polarity of a pair

44、 of nodes is determined by the ordering of the nodes. The reference polarity may be chosen arbitrarily. For two nodes, a and b, with the ordering ab, the voltage u ab is defined as uVV ab a b = = = , where V aand V bare the electric potentials at the nodes a and b, respectively. 5.3 Indication of th

45、e reference polarity First method: The reference polarity for a voltage is indicated by a line, straight or curved, with a plus sign (+) at the node that comes first in the ordering of the nodes (a in ab). If wanted, a minus sign may be attached to the other end of the line. The letter symbol repres

46、enting the voltage is placed close to the line (see Figure 5). Figure 5a Figure 5b Figure 5c Figure 5d Figure 5 Indication of the reference polarity by means of plus and minus signs The line may be omitted if there is no ambiguity in the grouping of nodes in terminal pairs. This is the case for indi

47、cating a voltage in a two-port network (see Figure 6). Page8 EN60375:200360375 IEC:2003 17 Two-port network Figure 6 Simplified indication of the reference polarity by means of plus signs Second method: The reference polarity of the voltage uuVV = = = = = ab a bis indicated by an arrow with its tail

48、 at the node that comes first in the ordering of the nodes (a in ab). The letter symbol representing the voltage is placed close to the arrow. See Figure 7. Figure 7 Indication of the reference polarity by an arrow Third method: The reference polarity for a voltage is indicated by a double subscript

49、 attached to the letter symbol representing the voltage, the first subscript being understood to correspond to the node that comes first in the ordering (a in ab). This means that uVV ab a b = = = . As in the first method, the letter symbol is placed close to a straight or curved line between the two nodes (see Figure 8). Figure 8 Indication of