ABSTRACT
Transient recovery voltage (TRV) refers to the voltage appearing across circuit breaker contacts a¶er it interrupts current. e circuit breaker must withstand TRV in order to complete the current interruption process. For circuit breakers rated above 1 kV, the TRV is a crucial application criterion, along with several other important factors:
1. Voltage rating 2. Interrupting current ratings 3. Capacitive current switching (inrush, outrush, close-and-latch ratings) 4. Out-of-phase switching 5. Generator breakers pose a special case due to asymmetrical current interruption
TRV is not a consideration for low-voltage circuit breakers rated 1 kV or less, but above 1 kV, every circuit breaker application should include TRV analysis. e rest of this section introduces TRV calculations and mitigation, at a level sužcient for educational purposes. For actual design work, the user should have access to one of the standard application guides (IEEE C37.011-2005, 2005; IEC 62271-100, 2008). In some cases, time-domain simulation in an electromagnetic transients (EMT) program is necessary.
