This application guide applies to ac high-voltage (> 1000 V) circuit breakers rated for shunt reactor switching. This application guide provides the theoretical background of shunt reactor switching and how information obtained from test results should be used to predict overvoltages in the field, and gives suggestions how to mitigate these overvoltages.
Purpose
This guide is intended for general use in the application of ac high-voltage circuit breakers for shunt reactorcurrent switching.The current to be interrupted is generally less than 300 A rms; however, shunt reactor switching imposes a unique and severe duty on the connected system and the circuit breaker. Successful interruption is the result of a complex interaction between the circuit breaker and the circuit; this interaction can result in significant overvoltages. The purpose of the guide is to describe, principally for the benefit of the user, the shunt reactor switching duty, the overvoltages generated, and the control of those overvoltages. The guide further details the specification of circuit breakers and procedures to predict field performance based on test data.NOTE--Shunt reactors connected to the tertiary windings of transformers have typical currents in the order of some thousand Amperes.
Abstract
Revision Standard - Active.Guidance for the application of ac high-voltage circuit breakers for shunt reactor switching is provided. Overvoltage generation for the three cases of shunt reactors being directly grounded, ungrounded, or grounded through a neutral reactor is addressed in terms of derivation and limitation methods. Circuit breaker specification for the purpose and the use of laboratory test results to predict field performance is also covered by this guide.
