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Line-commutated converter (HVDC classic) are made with electronic switches that can only be turned on. Voltage-sourced converters are made with switching devices that can be turned both on and off. Line-commutated converters (LCC) used mercury-arc valves until the 1970s, [6] or thyristors from the 1970s to the present day
The converter is usually installed in a building called the valve hall. Early HVDC systems used mercury-arc valves, but since the mid-1970s, solid state devices such as thyristors have been used. Converters using thyristors or mercury-arc valves are known as line commutated converters. In thyristor-based converters, many thyristors are ...
This is one of the lowest ESCR values ever achieved with a line-commutated HVDC converter. McNeill was also the first HVDC station to use three-phase, four-winding converter transformers. The transformers, which are connected to 138 kV on the Alberta side and 230 kV on the Saskatchewan side, are each equipped with a 25 kV tertiary winding (to ...
The basic building-block of a line-commutated HVDC converter is the six-pulse bridge. This arrangement produces very high levels of harmonic distortion by acting as a current source injecting harmonic currents of order 6n±1 into the AC system and generating harmonic voltages of order 6n superimposed on the DC voltage.
HVDC electrodes are used in most bipolar thyristor-based line-commutated converter (LCC) HVDC transmission systems as a means to improve the reliability of the entire system while also reducing the DC voltage and current ripples. In the event that one of the poles in the bipolar system is faulted, the current path will switch to ground return ...
Electric power transmission through interconnectors using high-voltage direct-current (HVDC) involves usually two converter stations and a transmission line. Generally overhead lines are used, but an important class of HVDC projects use submarine power cables. A back-to-back station has no transmission line and joins two separate AC grids at a ...
Line commutated converter technology is used at each HVDC converter to maximise the amount of electrical power that can be transferred, which is predominantly exported from renewable sources in Scotland. This type of HVDC conversion technology means that large filter halls are required at each converter station. [10]
A back-to-back connection for electric power transmission is a high-voltage direct-current (HVDC) system with both ends in the same switchyard. This is used to couple asynchronously operated power grids or for connecting power grids of different frequencies where no DC transmission line is necessary.