Parasitic Inductance of Surge Protective Devices for a Wide Frequency Range

Abstract:
This work investigates the efficacy of different experimental and simulation methodologies in determining the parasitic inductance of surge protective devices for a broad frequency spectrum. This is important since the inductive behavior of surge protective devices affects their maximum residual voltage, thus also the protection offered in the case of fast-front transients exhibiting high current derivatives. The parasitic inductance of a commercially available DIN rail surge protective device is determined by utilizing a dummy surge protective device with the voltage limiting component (varistor) replaced by a copper block. Parasitic inductance estimations are made by employing: i) dielectric spectroscopy measurements, ii) impulse current tests, and iii) finite element analysis simulations; results are discussed in terms of the accuracy of the proposed methods and associated challenges in determining the parasitic inductance.