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Synthetic current test for HVDC circuit breakers

A 12-pulse rectifier is used as the current source to supply the DC test current and a voltage oscillation circuit is used to supply the recovery voltage after current switching. An auxiliary circuit breaker and a spark gap are implemented in the circuit to connect these two sources to the test object at specific time interval. Description of the figure:

  • The 12-pulse rectifier is controlled to generate a DC test current to the test breaker (TB) through smoothing reactor (Ls) and auxiliary breaker (AB1) at a relative low generator driving voltage.
  • AB1 and TB open simultaneously and DC current arcs are established inside the interrupting chambers of these breakers
  • Spark gap in the voltage circuit is ignited at the instant that the arcing time of TB will be equal to the prospected value
  • AB2 closes and bypasses the DC current
  • AB1 clears as the DC current transfer from AB1 – TB branch to AB2 bypass branch
  • TB is stressed by the injection current alone from the voltage circuit after AB1 clears
  • TB clears at injection current zero crossing and withstands a transient recovery voltage and subsequent DC voltage afterwards
  • DC source rectifier’s is blocked by stopping firing signal sending
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Source
A Synthetic Test Circuit for Current Switching Tests of HVDC Circuit Breakers by Baoliang Sheng, Senior Member, IEEEDag Andersson and Anders Henriksson: “Passive and Active DC Breakers in the Three Gorges Changzhou HVDC Project”; in proceeding of 2001 International Conference on Power Systems (ICPS2001), pp. 391-395

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