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 and the effects 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 the 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
· Overview and definitions
2. Oscillatory Circuits
· Basic principles of current interruption in circuit breakers
· General approach to series and parallel RLC oscillatory circuits
3. Pole Factor Calculation
· Underdamping, critical damping and overdamping
· Damping factors
· Amplitude factors
· Basic theory and general approach to using symmetrical components
4. Travelling Waves
· Balanced and unbalanced fault calculations
· AC recovery voltage calculations
· First, second and third pole factors
· Basic concepts
5. Terminal Faults
· Open circuit and short circuit termination cases
· Circuit breaker rating basis
6. Short Line Faults
· 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
· Line side travelling waves
7. Out-of-Phase Switching
· TRV calculation
· TRV considerations
8. Inductive Load Switching
· Shunt reactor switching
9. Capacitive Load Switching
· Unloaded transformer switching
· Shunt capacitor bank switching
· Unloaded transmission line switching
· Unloaded cable switching
David Peelo, Ph.D., P.Eng, C.Eng, FIEE – DF Peelo & Associates Ltd.
Dr. David Peelo, consultant and former switching specialist at BC Hydro; active Cigre member; Convenor IEC MT32 (inductive load switching), IEC PT42 (current interrupting capability of air break disconnectors) and member IEC MT57 (Application guide for IEC 62271 100 and other circuit breaker related standards). He is an IEC 1906 Award recipient, a Distinguished Member of Cigre and the author of a textbook on current interruption transients calculation.