Because the computational complexity of the di/dt at current zero and TRV peak value ucfor asymmetric short-circuit current interruption

in this paper

the equivalent circuit models have been established for asymmetrical short-circuit fault breaking to gain the math expressions of di/dt at current zero and TRV peak value ucin the major loop and minor loop

in addition the di/dt and ucwith the same expression. By simplified the expression of ucin the appendix P of GB 1984—2014

the derived conclusion is verified which is right. Therefore

it can use the expression of di/dt to modify ucfor asymmetric short-circuit current interruption. The calculation results show that the correction error is proportional to the percentage of DC component p and the peak time t3

and Δucis increased when the time constant τ increasing. However

the error can meet the test requirements well. Finally

the calculated values of di/dt and Δucare given in this paper

which can provide the theory and reference basis for the test-duty T100 a.