IEC 60375 pdf download

IEC 60375 pdf download Conventions concerning electric and magnetic circuits
1 Scope
This International Standard lays down rules for signs and reference directions and referencepolarities for electric currents and voltages in electric networks，as well as for thecorresponding quantities in magnetic circuits.
ln Clauses 3 to 9,the time dependence is arbitrary. Clause 10 details the rules and recom-mendations for complex notation.
2Normative 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 editionof the referenced document (including any amendments) 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
3Terms and definitions
For the purposes of this document, 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 ornetworks
[lEV-131-11-11]
NOTE 1 For an electric circuit element, the terminals are the points at which or between which the related integralquantities 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, mathematical model of a device characterized by one or more relationsbetween integral quantities
[IEV-131-11-03]
3.3
two-terminal element
electric circuit element having two terminals
[IEV 1 31 -1 1 -1 6]
3.4
n -terminal circuit element
electric circuit element having n terminals with generally n > 2
[IEV-1 31 -1 1 -1 3]
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 ideal circuit elements and their interconnections, considered as
a whole
[IEV-1 31 -1 3-03]
NOTE 1 The term “electric network” is defined in IEC 60050-1 31 -1 1 -07 and in IEC 60050-1 51 .
NOTE 2 In diagrams in this standard, a box, IEC 6061 7 symbol, represents any network, unless otherwise specified.
3.6
branch
subset of a network, considered as a two-terminal circuit, consisting of a circuit element or a combination of circuit elements
[IEV-1 31 -1 3-06]
3.7
node, vertex (US)
end-point of a branch connected or not to one or more other branches
[IEV-1 31 -1 3-07]
3.8
loop
closed path passing only once through any node
[IEV-1 31 -1 3-1 2]
3.9
tree
connected set of branches joining all the nodes of a network without forming a loop
[IEV-1 31 -1 3-1 3]
3.1 0
co-tree
set of the branches of a network not included in a chosen tree
[IEV-1 31 -1 3-1 4]