PES Web-based Tutorial Series: Understanding Transient Recovery Voltages and Their Measurement in Substations, Session 3: Load Current Switching Transient Recovery Voltages (Slides)

Transient recovery voltages (TRVs) are the voltages imposed on circuit breakers immediately after current interruption. The principal cases of interest are the interruption of the currents associated with terminal faults, short line faults and out-of-phase switching and breaking capacitive and inductive load currents. Each case is discussed in detail explaining the origin and derivation of the attributes associated with the TRVs including pole factors, amplitude factors, two and four parameter representations and travelling waves where applicable. Instrumentation for field measurement of TRVs will be discussed. Practical field issues such as sensor size and location, the challenge of using electric sensors that effectively change the circuit under test will be discussed. Use of optical voltage and current measurement techniques for “non-intrusive” measurement will be discussed in detail.