THE reference for power system transients

ZnO Arrester Models

Viewing 3 posts - 1 through 3 (of 3 total)
  • Author
    Posts
  • 31 July 2025 at 11h01 #6649
    anonymous
    Keymaster

    After generating ZnO surge arrester using Zno Data Function we obtain a punch card which we can use for any surge arrester from a particular model and manufacturer for any rated voltage.

    What value of Vref do we need to enter in order to scale the data?

    For example – I produced a 96kV rated surge arrester .pun card – then wanted to convert it to a 120kV rated equivalent. The Zno Data Functionrecommends we use 2 x Vrated when generating the data – ie 192kV. In the ZnO model for the 120kV rated equivalent should I make Vref = 240kV ?

    Why can’t I make Vref = Vrated to simplify things?

    Any help would be appreciated.

    31 July 2025 at 11h01 #6651
    anonymous
    Keymaster

    For numerical stability purposes only, the program suggests that you use 2 x V rated. But other values function also in most cases

    To convert an already functionnal arrester model, you only need to multiply the Vref value by a proportion. For your exampe this proportion in your case is 120/96.

    31 July 2025 at 11h02 #6652
    anonymous
    Keymaster

    Someone could help me to modelling ZnO surge arrester?

    Details are as follows:

    – SIEMENS

    – Duty cycle voltage: 96 kV

    – MCOV: 76 kV

    – TOV capability: 109 kV (for 1 s) and 102 kV (for 10 s)

    – Protective level (Maximum discharge voltage):

       * FOW 10 kA:259 kV

       * for 8/20 us (impulse):

         – at 1.5  kA: 202 kV

         – at 3.0  kA: 214 kV

         – at 5.0  kA: 221 kV

         – at 10.0 kA: 235 kV

         – at 15.0 kA: 252 kV

         – at 20.0 kA: 263 kV

         – at 40.0 kA: 294 kV

       * for 45/90 us (impulse):

         – at 500  A: 188 kV

         – at 1.0  kA: 195 kV

         – at 2.0  kA: 204 kV

    Appreciate your help,

     

    Saulo Hernandez

  • Author
    Posts
Viewing 3 posts - 1 through 3 (of 3 total)
  • You must be logged in to reply to this topic.