Minutes:

Chairman prepared and chaired the meeting.  He reminded everyone that some members that volunteered to submit parts of the Guide have not submitted their parts.  The draft of the Guide has been rewritten in IEEE Standard format and it will be available for review when all parts are received.  It should be done before the next meeting to finalize documents for changing status from Discussion Group to Working Group.

The Chairman introduced Mr. Sudhakar Cherukupalli of BC Hydro who gave a thorough presentation on BC Hydro experience with the use of a fiber optic sensor inserted in 525kV self-contained fluid-filled submarine cable.

After the presentation and a brief discussion on the presentation, the group went to formal meeting.

Mr. Chaaban handed out the scope and objective of the Guide for discussion.  Some of the members corrected the handouts during the meeting.  During the discussion that followed, Mr. Jay Williams proposed including both off-line and real-time system evaluation.  Mr. John Cooper discussed details and scope of the real-time calculation.  The Group discussed also if the cable modeling should be included in the Guide.  Mr. Jay Williams and Rusty Bascom suggested some changes to the title of the Guide.  Mr. Chris Grodzinski suggested use of the DTM abbreviation as opposed to the DTS because the latter is used in one of the manufacturer model name.  However, there was no consent of all members.

Mr. Pierre Argaut submitted his part of the Guide related to the use of this method in Europe.  Mr. John Cooper submitted corrected list of publications to be included in Bibliography of the Guide.

The group met on Monday, November 1, 2004 at 2:00 PM.  The following members and guests were present:

Minutes:

The Chair welcomed attendees and presented a group member list to confirm validity of the contacts details because we are entering a phase of evaluating the draft.

Mohamed Chaaban presented a CIGRE project 247, which is similar in nature to the scope of the C24D group, for members’ evaluation.

Since the group prepared main framework of the guide a detailed scope of the guide was discussed to get consent of the group members for PAR application.

SCOPE : This guide presents an overview of the existing and emerging thermal monitoring systems related to cable installations and outlines the calculation procedures to evaluate, with high confidence, the current rating in real time. It summarizes the risks, costs and benefits associated with simpler, less costly systems based on discrete temperature measurement with thermocouples, RTD’s, thermistors, etc, compared with more sophisticated and more expensive systems like the new emerging one based on distributed temperature measurement. The various rating calculation methods are also presented, namely the conventional analytical method of Neher MacGrath and the more recent one based on the numerical methods using finite element or finite difference techniques. This guide addresses also the various aspects of user-interface and data communication issues needed to make the system more effective and more user-friendly.

OBJECTIVE: The purpose of this guide is to assist potential users in making an informed decision prior to purchasing and operating a real time monitoring and rating system by addressing the following major issues:

• Type of cable system installation: existing or new
• Circuit length, type of terrain and backfill along the cable route that may favor the use of distributed rather than discrete temperature measurement or vice versa
• Cost-benefit of using a real time monitoring and rating system vs. a calculated limit
• System complexity, performance, reliability and maintenance
• Recommended operating criteria with trend forecasting
• Influence of adjacent circuits
• System contingencies and acceptable risk

There were several comments about contents of the Scope with regards to:

• spelling
• inclusion of the cost aspect of different methods – agreed not to include cost rating of different methods
• removing certain words as not to suggest solution
• Jay Williams suggested rephrasing of the Scope’s section related to the objective of the real-time monitoring.
• Mohamed Chaaban informed that he will apply for PAR when most of the issues raised by participants are resolved to minimized time for guide approval.

A corrected Draft in the IEEE format was distributed to the attendees. The Chair asked members to comment on:

• including introduction which would compare existing manual dynamic rating with real time rating.
• a heated discussion erupted regarding real time rating: what to include in the guide. Participants agreed that some background on different levels of precision and dynamic rating complexity should be included.
• what is necessary for calculation cable rating at any given time and predictability for the future.

Sudhakar Cherukupalli of BC Hydro delivered an excellent presentation of the second phase of the 525kV line monitoring project performed by BC Hydro.