March 2017

Current Interruption Transients Calculation

Please Note
Please bring a calculator and a laptop loaded with Excel for the classwork.
Status: This course is cancelled due to lower than expected registration.
Date: Tuesday, March 28, 2017 - Thursday, March 30, 2017
Time: 8:30 AM – 9:00 AM: Registration and Continental Breakfast (Day 1-3)
9:00 AM – 5:00 PM: Current Interruption Transients Calculation (Day 1-3)
Location: Vancouver, BC
Presenter: Dr. David Peelo, P.Eng.
DF Peelo & Associates Ltd.
Credit: 21 Formal Professional Development Hours (PDH)
Cost: Early Bird Price Engineers and Geoscientists BC Member: Current Interruption Transients Calculation - Day 1 : $1150.00 + GST = $1207.50 until Mar 14, 2017

Engineers and Geoscientists BC Member and EIT/GIT Regular Price: Current Interruption Transients Calculation - Day 1 : $1350.00 + GST = $1417.50

Non-Member Price: Current Interruption Transients Calculation - Day 1 : $1350.00 + GST = $1417.50

Student Member Price: Current Interruption Transients Calculation - Day 1 : $675.00 + GST = $708.75
Please Note: *A minimum number of registrations are needed by March 14, 2017 to proceed with this seminar. Please register early to avoid cancellation.
**All prices are subject to applicable taxes.
Contact: Jennifer Chan | Professional Development Coordinator
Direct: 604.412.4861
Toll Free: 1.888.430.8035 ext.4861
Fax: 604.639.8180
Email: [email protected]
Note: Please bring a calculator and a laptop loaded with Excel for the classwork.
An advanced and comprehensive course on transients associated with making and breaking fault currents and capacitive and inductive load currents.


This advanced course covers the origin and derivation of the transient recovery voltage (TRV) requirements for circuit breakers applied for fault clearing and the switching of inductive and capacitive loads. The course first develops the fundamental concepts involved in current making and breaking including oscillatory circuits, pole factors, and travelling waves. The developed concepts are then applied to the individual current interruption case TRVs and associated reignitions or restrikes and to making and breaking capacitive and inductive circuits. All cases are well illustrated by real examples. At the end of the course, attendees will have an in-depth knowledge and understanding of the TRV requirements in IEC and IEEE standards and also know how to deal with exceptional cases.

What You Will Learn

  • Fundamental basis for TRVs and reignition and restriking transients.
  • Generic approach to the calculation of TRVs and reignition and restriking transients.
  • Derivation of pole factors and amplitude factors associated with TRVs as specified in IEC 62271-100 and IEEE C37 Series.
  • Calculation of the effects of adding surge capacitors to control TRVs, effect of shunt capacitor banks, load sharing reactors, and opening resistors.
  • Calculation of TRVs and reignition and restriking transients associated with inductive and capacitive loads, respectively.


To benefit from this course, attendees should have a basic prior knowledge of the following:
  • Electric circuit theory.
  • Differential equations.
  • Trigonometric and exponential functions.
  • Symmetrical components.
  • IEC Standards 62271-100 and 62271‑110 or IEEE C37 Series.
  • Use of Excel for equation-based calculations.


  1. Introduction
    • Overview and definitions.
    • Basic principles of current interruption in circut breakers.
  2. Oscillatory Circuits
    • General approach to series and parallel RLC oscillatory circuits.
    • Underdamping, critical damping, and overdamping.
    • Damping factors.
    • Amplitude factors.
  3. Pole Factor Calculation
    • Basic theory and general approach to using symmetrical components.
    • Balanced and unbalanced fault calculations.
    • AC recovery voltage calculations.
    • First, second, and third pole factors.
  4. Travelling Waves
    • Basic concepts.
    • Open circuit and short circuit termination cases.
  5. Terminal Faults
    • Circuit breaker rating basis.
    • Four-parameter and two-parameter TRVs.
    • "Standard" circuit for TRV derivation.
    • 100% and 60% terminal faults.
    • 30% and 10% terminal faults.
    • Effect of shunt capacitors, load-sharing reactors and opening resistors.
    • Double earth faults.
    • Asymmetrical fault currents.
  6. Short Line Faults
    • Line side travelling waves.
    • TRV calculation.
  7. Out-of-Phase Switching
    • TRV considerations.
  8. Inductive Load Switching
    • Shunt reactor switching.
    • Unloaded transformer switching.
  9. Capacitive Load Switching
    • Shunt capacitor bank switching.
    • Unloaded transmission line switching.
    • Unloaded cable switching.


Dr. David Peelo, P.Eng.
DF Peelo & Associates Ltd.

Dr. 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 at the ASEA Power Transmission Products Division 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 current interruption transients and surge arrester application. He is an active IEEE and Cigre member and is a past Convenor of IEC MT32 (Inductive Load Switching), the Convener of IEC PT42 (Current interrupting capability of air break disconnectors) and a member of IEC MT57 (Application guide for IEC 62271 100 and other circuit breaker related standards). He is an IEC 1906 Award recipient and a Distinguished Member of Cigre. He has authored or co-authored over 70 papers on circuit breakers and surge arrester application, 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.

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