IEC 60700-2:2021 pdf free download – Thyristor valves for high voltage direct current (HVDC) power transmission
1 Scope
This part of lEC 60700 defines terms for thyristor valves for high-voltage direct current (HVDC)power transmission with line commutated converters most commonly based on three-phasebridge connections for the conversion from AC to DC and vice versa.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document andare indispensable for its application.For dated references,only the edition cited applies. Forundated’references,the ‘latest edition of the referenced document (including anyamendments) applies.
IEC 60027(all parts),Letter symbols to be used in electrical technology
IEC 60633,Terminology for high-voltage direct current (HVDC) transmission
3 Symbols and abbreviations
3.1General
The lists in 3.2 and 3.3 cover only the most frequently used symbols.The lists of symbols ofthe lEC60027 series and lEC 60633 apply.
4.1 converter arm
part of a bridge connecting two points of different potentials within a bridge,for examplebetween an AC terminal and a DC terminal
Note 1 to entry: The main function of a converter arm is conversion.4.2 converter bridge equipment used to implement the bridge converter connection, if usedSEE: Figure 1
Note 1 to entry: The term “bridge” may be used to describe either the circuit connection or the equipmentimplementing that circuit.
[SOURCE: IEC 60633:2015,6.2,modified – The expression “and the by-pass arm” has beendeleted from the definition.]
4.3 converter unit
indivisible operative unit comprising all equipment between the point of common coupling onthe AC side and the point of common coupling on the DC side,essentially one or moreconverter bridges,together with one or more converter transformers,converter unit controlequipment,essential protective and switching devices and auxiliaries， if any，used forconversion SEE: Figure 1
Note 1 to entry: lf a converter unit comprises two converter bridges with a phase displacement of 30 degrees,then the converter unit forms a 12-pulse unit.
5.1 forward directionconducting direction
direction of current through a valve，when current flows from the anode terminal to thecathode terminal
5.2 reverse direction non-conducting direction
direction of current through a valve，when current flows from the cathode terminal to theanode terminal
6 Thyristor valve design
6.1 thyristor
bi-stable semiconductor device comprising three or more junctions which can be switchedfrom the off-state to the on-state
Note 1 to entry: Devices having only three layers but having switching characteristics similar to those of four-layers devices may also be called thyristors.
Note 2 to entry: The term “thyristor” is used as a generic term to cover the whole range of PNPN type devices. ltmay be used by itself for any member of the thyristor family when such use does not result in ambiguity or misunderstanding. In particular, the term “thyristor”is widely used for reverse blocking triode thyristor，formerlycalled “silicon controlled rectifier”.
Note 3 to entry: Thyristors may either be electrically triggered thyristor (ETT)or light triggered thyristor (LTT).