Electrical and power engineering

Short-circuit resistance

 

 

Short-circuit resistance

VUM evaluates switchgear with rigid tubular conductors and conductor cables in terms of thermal and mechanical strength for defined load cases including short circuits. The primary technical checks are supplemented by external services to assess the statics of foundations and supporting structures. If the short-circuit resistance of an existing system cannot be confirmed or can only be partially confirmed, VUM works with a structural engineer and in coordination with the client to develop catalogs of measures to improve short-circuits or strengthen the systems examined.

Our services

  • Local survey of the system and compilation of the as-built documentation (on request using a terrestrial laser scan and additional natural measurements)
  • Determination or verification of the static cable pull forces depending on the cable curve shape (cable curve calculation and verification using laser scan)
  • Checking the primary technology of high-voltage switchgear according to EN 61936-1 (high-voltage switchgear), EN 60865-1 (effect of short-circuit currents) and EN 62305-1 (lightning protection)
  • Calculation of the thermal and mechanical effect of short-circuit currents according to EN 60865-1
  • Advice and definition of possible upgrade scenarios (if necessary) with the client
  • Joint assessment of the structural and foundation statics with a civil engineer for statics
  • Creation of catalogs of measures for upgrading or reinforcement measures (if necessary)
  • Proof of short-circuit resistance in cooperation with a civil engineer for statics
  • Technical support of the implementation

The graphical representations of the images below first show the transformer overvoltage (framed in orange). Due to the modeling of the complex rope curve in the profile, the representation is distorted, as a look at the scaling of the axes shows.

The static cable pull forces are calculated for each of the curves shown, which correspond to the specified load cases. As a check, the calculated cable curve is superimposed on the cable curve recorded by laser scanning.