WG C4.305 Practices in Insulation Coordination of Modern Electric Power Systems Aimed at the Reduction of the Insulation Level

Background :

It is known that within former SC 33 (one of the predecessors of SC C4) an international survey was  organized on Insulation Coordination (IC) practice and service experiences. That survey was limited to countries of SC 33 members only and was organized and discussed between 1995 and 1998. Few similar surveys have been carried out in some other countries or utilities, although ten or fifteen years ago. According to these surveys – incorporated into database of several utilities – some improvements appear to be achievable concerning IC practice in modern electric power systems, such as the reduction of insulation levels for entire networks or for some important components, and the effective limitation of overvoltage by means of adequate modern procedures and measures. Also, the growing need for unification of IC practice on interconnected lines - taking into account the influence of IC on life expectancy - was emphasized, and the presence of last-generation power electronic devices on IC practice was mentioned worth of additional investigation.  Due to many technological and organizational changes in power system developments in last decades, and due to the increase of networks interconnections, it is reasonable to carry out new survey on various tendencies of application of IC discipline in modern power systems.

Scope :

The new Working group will focus on:

  • Current status of IC practice in the world collected by a new survey based on new developed forms
  • Review of insulation levels in HV, EHV and UHV AC networks and important network elements
  • Analysis of reliable failure rates data collected in various networks, utilities and countries
  • Specific questions of IC practice in network interconnections between various utilities and countries
  • Review of modern measures for suppressing overvoltages and limiting electrical stresses
  • Recommendation for reduction of insulation level in modern power systems.

A CIGRE Guide will be produced, and the Summary will be published in “Electra”.

Convener: A. S. Telento (Croatia) 


Progress Report 2014 (pptx, 300kB)