Guide for the Application of Shunt Reactor Switching
|Publication Date:||9 December 2009|
This application guide applies to ac high-voltage circuit breakers rated for shunt reactor switching.
The guide covers the specific cases of switching directly grounded shunt reactors, ungrounded shunt reactors, and shunt reactors grounded through a neutral reactor. Directly grounded reactors are common on systems having a voltage of 60 kV and above, whereas ungrounded reactors are commonly applied on systems having a voltage below 60 kV. Schemes where the reactor is grounded through a neutral reactor are usually applied only on systems having a voltage of 60 kV and above.
Whereas this application guide is directed toward circuit breakers, it is recognized and accepted that other switching devices such as high-voltage load break switches and circuit switchers are capable of shunt reactor switching and this guide may be applied as appropriate.
This guide is intended for general use in the application of ac high-voltage circuit breakers for shunt reactor current 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.