Circuit-breaker behaviour in reactor switching: applicability and limitations of the concept of chopping number

The author reviews some of the theory leading to definition of a chopping number related to the chopping behavior of circuit breakers interrupting small inductive currents. The possibility of using this number to model circuit breakers in digital calculations is discussed, a comparison being made with the alternative of simulating the dynamic behavior of circuit-breaker arcs by differential equations. The importance of a correct appraisal of the frequency dependence of circuit parameters, especially capacitances, in both methods, is demonstrated using an example.<>