1. CIGRE WG C PRACTICES IN INSULATION COORDINATION OF MODERN ELECTRIC POWER SYSTEMS AIMED AT THE REDUCTION OF INSULATION LEVELS
WG Composition:
WG Convenor: A. S. TELENTO (Hr)
WG Secretary: S. MALGAROTTI (It)
Total number of Members (Reg.+ Corr.)
Number of Regular members:
Number of Corresponding members:
Number of members from industry (utilities):
Number of members from industry’s institutes:
Number of members from universities (Edu., R&D): 2
Number of members from consulting companies: 4

2. Technical Committee meeting, September 1st, 2012 - Paris
CIGRE WG C4.305
Number of countries represented: Total number: 12
Number of countries from various continents: Europe: 9, South America: 2, North America: Asia, Africa, Australia: 0 (no participants)
Conclusion: Countries from non-included continents are expected to be included in WG Survey and WG work (e.g. Japan, China, India, RSA…) Members of SC C4 are kindly requested to act in that direction. .
WG Title matters:
Original Title proposed in 2008 was:
Insulation Coordination Practices and Tendencies in Modern EPS
Changed Title (made by former SC Chairman C.A. Nucci in 2009):
As in Title of this presentation – Consequences: Scope is focused to Ins. Level reduction – it changes to some extent the Scope of WG
New slight change: Insulation Coordination Practices in Modern EPS aimed at the reduction of Ins. Levels (change in sequence of first three words) – that gives more stress in title on IC discipline
Technical Committee meeting, September 1st, Paris

3. Technical Committee meeting, September 1st, 2012 - Paris
CIGRE WG C4.305
WG Timeline (1):
Proposal of new WG given at the beginning of 2008
Date of approval: Signed by TC Chairman at the end of Nov. 2009
Information received by WG Convenor at the end of 2009
Beginning of WG work in the middle of 2010 (no sufficient answers received before spring 2010 from experts interested to work as WG members)
Starting Dates: First informal meeting in Zagreb, Croatia, April 2010
First official WG Meeting in Paris, August 26, 2010 (14 participants)
Second official WG Meeting, Rio de Janeiro, April 12, 2011,
hosted by ONS and Mr. Dalton Brasil (7 participants)
Third official WG Meeting: Paris August 28, 2012 (8 participants)
Fourth official WG Meeting: Paris, August 27, 2014
Totally: 4 WG Meetings and additional 3 informal meetings in Zagreb
have been held
Number of Internal Working Documents (IWD) discussed and
dispatched among WG Members: 22 (IWD 1 – IWD 22).
Technical Committee meeting, September 1st, Paris

4. CIGRE WG C4.305 WG Timeline (2):
In WG Meeting was planned in Zuerich, but was not held due to
unexpected infeasibilness of WG Convener. Details have been given to
current SC C4 leadership. Due to same reason activity of WG 305 was
slowed down or stopped for about 18 months (up to middle of 2014).
Low-level intensity work in mentioned period (2013 to middle of 2014)
was limited to the following:
- exchange of some new IWDs among WG Members
- inclusion of few new WG Members (e.g. A. Xemard, V. Larin etc.)
- preparations for quick finishing of WG work in period after Paris
Session 2014, etc.
Expected date of submitting Final Report to SC Chairman:
Final report will be submitted about half a year after Paris Session
2014, i.e. in spring 2015, after processing WG Survey on IC Practice .

5. CIGRE WG C4.305 WG Timeline (3):
Graphical presentation of events in WG formation and work: .
First idea The first Approval of
on new informal new WG by First part of work o WG C Period of Second part of
WG given Meeting TC Chairman forced break of WG 305 work
on CIGRE on new WG at the end of WG C4.305 work and Final Report
Symposium in Cavtat, year and after submission to
in Zagreb, Croatia months of SC Chairman
Croatia submitting
WG request
_↑__₀____↑_₀_____↑₀____↑₀↑₀↑₀₀↑₀
LEGEND:
Thin line __ : Development of idea of new WG, Long period of WG approval by TC
Red arrow  : Period of active work of WG with regular WG Meetings
White arrow  : Period of inactivity or low intensity work
Vertical arrow ↑: WG Meetings

6. TABLE OF CONTENTS 0F NEW CIGRE BROCHURE - TB WG C4.305
CIGRE WG C4.305
TABLE OF CONTENTS 0F NEW CIGRE BROCHURE - TB WG C4.305
Technical Committee meeting, September 1st, Paris

7. CIGRE WG C4.305 Highlights of Recent Activity (1)
Survey forms for gathering world-wide practice in IC consist of:
I System parameters: IV Withstand voltages:
Operating voltages  Transformers
Neutral earthings  Switching equipment
Design altitudes  Substation insulation
II Overvoltage determining parameters:  Line insulators
Lightning activity (GFD) V Pollution parameters:
Transmission towers configuration  Class (ESDD, NSDD)
Substation size and configuration  Creepage distances
Capacitor banks and circuit breakers VI Insulation failure rates:
Maximum overvoltages in system  Experienced data
III Surge arrester application:  Acceptable levels
Ratings VII Insulation level tendency
Locations  Reductions

8. CIGRE WG C4.305 Highlights of Recent Activity (2):
Example of diagram in textual part of Brochure:

9. CIGRE WG C4.305 Future activities:
Despatch of survey forms to power utilities and countries:
through WG C4.305, through SC C4 Members, NCs Cigre etc.
Term: September 2014
Filling of survey, with possible help of WG or SC Members
Term: till end of 2014
Gathering and processing data from world’s survey
Term: the first quarter of 2015
Despatch of TB C4.305 Report to SC Chairman till June 2015
Inclusion of SC C4 in work of this WG, generic to part of SC C4:
Letter of recommendation of SC C4 Chairman, approval of proposal of Letter: in September 2014
RM and OM of SC C4 are expected to help in interactive work with utilities and countries (such duty arises from SC Rules)
SC Rule 5.5 “… processing of questionnaires issued by SC”

10. Thanks for your Attention! Special Thanks for your very kind
Assistance to this Project!
CIGRE WG C4.305
Technical Committee meeting, September 1st, Paris