IEC 60700-2-2021 pdf free download – Thyristor valves for high voltage direct current (HVDC) power transmission – Part 2: Terminology.
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.
2Normative 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 ‘latestedition of the referenced document(including anyamendments) applies.
IEC 60027(all parts),Letter symbols to be used in electrical technologyIEC 60633,Terminology for high-voltage direct current (HVDC) transmission
3 Symbols and abbreviations
3.1 General
The lists in 3.2 and 3.3 cover only the most frequently used symbols. The lists of symbols ofthe lEC 60027 series and lEC 60633 apply.
3.2List of letter symbols
a(triggerlfiring) delay angle(triggerlfiring) advance angleucommutation overlap angler extinction angle
3.3 List of abbreviations
The following abbreviations are always in capital letters and without dots:
ETTelectrically triggered thyristor
LTTlight triggered thyristor
Tcu thyristor control unit
HVDChigh-voltage direct current
VBEvalve base electronics
MVUmultiple valve (unit)
BODbreakover diode
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 Converter performance
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
6Thyristor 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.
6.2
electrically triggered thyristor
ETT
thyristor triggered by applying electrical pulses to the thyristor gate Note 1 to entry: This note applies to the French language only.
6.3
light triggered thyristor
LTT
thyristor triggered by applying light pulses to a photosensitive area within the thyristor gate area
Note 1 to entry: This note applies to the French language only.
6.4
damping circuit
snubber circuit
circuit (usually consisting of a series connected resistor and capacitor) connected in parallel to a thyristor to reduce the amplitude of the extinction overshoot voltage
6.4.1
damping capacitor
snubber capacitor
capacitor connected in parallel to a thyristor (usually in series with a resistor) to reduce the amplitude of the extinction overshoot voltage
6.4.2
damping resistor
snubber resistor
resistor connected in parallel to a thyristor (in series with a capacitor) to limit the amplitude of discharge current of the snubber capacitor after thyristor turn-on.IEC 60700-2 pdf download.