Vysoké napětí

Locating ground connections based on detecting changes in the reverse part of voltage

11. 09. 2014

The quality and reliability of the electricity supply is greatly affected by breakdowns in electrical power networks, which must be promptly located and removed as soon as possible. In the case of single-pole breakdowns (connection of one phase and the ground) in ineffectively earthed systems, a ground connection occurs. This breakdown is extremely difficult to localize, which means it takes longer to remedy. We are offering a device which can quickly and precisely find this connection.

Description of the technology

Current methods of detecting ground connections do not represent an optimum solution for widespread use. The reason is that detection using current methods causes excessive interruption in the electricity supply in the distribution network due to inaccurate localization, or the localization of the breakdown may not be possible due to the complexity of high-voltage distribution networks.

Our new device eliminates the drawbacks of the current options of ground connection detection. The invention is based on a method for quickly and accurately finding the point of breakdown inside a distribution network, in particular in compensated networks where localization of a breakdown is most difficult. This comprehensive method enables the point of ground connection or asymmetrical short circuit to be localized inside a high-voltage distribution network which is operated as isolated, ineffectively or directly earthed. The new method uses recorded changes in the reverse parts of voltage and current, caused by asymmetry as a result of the breakdown, to localize the breakdown. Single changes to the reverse parts of voltage are monitored on the low voltage side of all or selected distribution transformers of the relevant system, and the reverse part of current is monitored at the point of the supply transformer, or in the single outputs of the feeding distribution station.

Main advantages

  • Precise determination of the points of asymmetrical breakdown inside extensive distribution systems
  • Saves time
  • Option for multiple localization of ground connection to increase precision
  • No need to detect affected output with ground protection
  • To determine the point of breakdown the method uses impedances which are already well known
  • Precision of the breakdown localization corresponds to the number of used voltage monitors – high variability according to the acceptable level investment and operational costs
  • Localization of breakdown is also possible in the event that several voltage monitors fail
  • The device can be also used for locating sources of pronounced non-symmetry in a distribution system
  • Voltage monitors used by the device can be also used for other purposes, such as measuring the characteristic values of voltage in low-voltage systems.

Protection of intellectual property

  • Utility model application has been filed
  • Czech patent application has been filed (in the priority deadline an option to extend protection to other countries)

Offer of collaboration

We are offering a licence, for those regions where the technology is protected, to a company which will ensure application of the equipment in the market.


Ing. Lukáš Novák, Technology Transfer Office, This email address is being protected from spambots. You need JavaScript enabled to view it.This email address is being protected from spambots. You need JavaScript enabled to view it., +420 541 144 227

Source of figure: Pastorius 2011 Wikimedia Commons

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