IEEE NZ North Section Lifelong Learning Series - October 2020

#Webinar #Power #System #Electricity #Environment #Eelctrical #Engineering

2020 Distinguished Lecture - Brought to you by PES NZ North Chapter

The IEEE NZ North Section Lifelong Learning Series is designed as a webinar series aimed at bringing in global experts and facilitate interaction with the members of the IEEE NZ North Section and wider NZ engineering fraternity. Each session will be organized by different societies under IEEE NZ North Section to ensure the diversity of the topics discussed.

Details of the upcoming session of the series brought to you by PES NZ North Chapter on 23rd October are as follows:

Speaker: Dr. David Peelo

               DF Peelo & Associates Ltd.


Topic     : Current Interruption in Atmospheric Air

Date      : 23rd October 2020

Time      : 1200-1330 hrs NZST


Note: Attendees are requested not to record the webinar as the materials used are protected. 

(Scroll down for Abstract of the Webinar and Speaker Biography)


  Date and Time




  • Date: 23 Oct 2020
  • Time: 12:00 PM to 01:30 PM
  • All times are (GMT+12:00) NZ
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Online through "Zoom Meeting"

The link will be shared via email close to the event.

  • Auckland, North Island
  • New Zealand

  • Contact Event Hosts
  • Starts 14 October 2020 12:00 AM
  • Ends 23 October 2020 01:00 PM
  • All times are (GMT+12:00) NZ
  • No Admission Charge


Dr. David Peelo Dr. David Peelo


Current Interruption in Atmospheric Air

Abstract of the Webinar: 

The principal function of air-break disconnectors in high voltage power systems is to provide electrical and visible isolation of a part of the system. Because the disconnectors are operated under energized conditions, they are required to interrupt the currents associated with the switching event. The currents in question are of low magnitude and can be inductive (unloaded transformer magnetizing current), capacitive (bus or short line charging currents) or loop currents (current transfer between parallel buses with a substation or between parallel lines). The opening operation results in free burning arcs in air between the fixed and moving disconnector contacts and rules with respect to current interruption capability are empirical.  Practice, particularly in North America, has been based on the ‘classic’ AIEE 1950 paper by Andrews, Janes and Anderson which related magnetizing and loop current magnitudes to the reach of the extreme point of the arc, all based on actual field tests. Later studies at BC Hydro and the Eindhoven University of Technology showed that the work of Andrew’s et al, however well-intentioned, was greatly flawed. The above-noted later studies starting in 1999 showed that very distinctive and unique features exist for each of the three current type arcs in terms how they evolve and interact with the circuit. The presentation will use mainly video material to explain the nature of the switching event when switching out unloaded transformers, breaking small capacitive currents and for loop switching. The use of auxiliary interrupting devices will also be discussed.


Dr. David Peelo is a consultant and former switching specialist at BC Hydro. He is a graduate of University College Dublin and Eindhoven University of Technology. He worked first for ASEA in Ludvika, Sweden and then for BC Hydro for 28 years rising to the position of Specialist Engineer. As a consultant, he has clients worldwide and in particular teaches continuing professional development courses on switching in high-voltage networks and surge arrester application. He is an active IEEE and Cigre member and chairs the IEC Canadian National Committee for Technical Committee 17 and Study Committees 17A and 17C. He is an IEC 1906 Award recipient, a Distinguished Member of Cigre and an IEEE Distinguished Lecturer. He is the author of a textbook on current interruption transients calculation and a co-author of a textbook on switching in transmission and distribution networks and a CIGRE Green Book on switching equipment.