The Secondary Arc Current Characteristic Analysis And Its Suppression Method Of UHV Half-wavelength AC Transmission Lines

In China, the energy resources is against the productive forces development, the base of energy in the west is about 3000km away from the load centers in the east, so the transmission systems with long distance and large capacity should be established. In this paper, based on the design example of ultra-high voltage (UHV) (1000kV) AC transmission system, the half wave-length AC transmission (HWACT) is introduced, and gives the line parameters calculation results (impedance matrix, admittance matrix and their symmetrical component matrix, etc.)when the transmission lines with circuit circulation transposition under triangle and horizontal arrangements; After deduction, presents a super-long transmission line secondary arc current calculation method, and the calculated results are validated by the electro-magnetic transient simulation software, then studied and calculated the secondary arc current of UHV half-wavelength ac transmission lines, analyzed its distribution trend and change characteristics along the line; Meanwhile, discusses the advantages and disadvantages of using fast grounding switches (HSGS) and changing line arrangement to suppress secondary arc current,finally gives suggestion parameter values of HSGS,which can provide as effective reference for the engineering practice implementation.