LAPLACE TRANSFORMATION APPLYING TO TRV MODIFICATION CALCULATION

摘要

The modification of the transient recovery voltage (TRV) is calculated by using a Laplace transformation for the current injection circuit simulating the current interruption circuit with the different conditions from a standard one. The TRV can be calculated in the current injection circuit by the product of the injected current and the power source impedance in a Laplace domain. The breaking resistor, the surge arrester and a parallel capacitance are added in parallel to the power source impedance to produce the modified TRV. In the case of the asymmetrical current interruption, the impedance is same as the standard case but the injected current is modified by the DC component. The result is confirmed to agree with the calculation result by EMTP for the parallel capacitor case. The result shows good agreements with the standard value at the asymmetrical current interruption.