According to the National Fire Protection Association, a study by Georges, Thomas, and others concluded that modern power grids are inherently susceptible to overvoltage because they employ equipment with low insulation levels, which is the root cause of more than 40% of unexpected electronic equipment failures. The cause was a lightning strike. Therefore, the field performance of surge protective devices (SPDs) has been extensively studied since the surge protection of low-voltage power supplies, where the power grid's reliability is crucial. 

Accurate SPD modeling is necessary to assess overvoltage mitigation properly, assess stress on protected equipment, and conduct sound risk assessment studies for direct and indirect lightning-related surges.
The experimental method for modeling they proposed is: a generalized equivalent lumped circuit model for surge protectors, which includes:

1) Integrating the inherent capacitance C S and switch S(V,t) of the voltage switching element (spark gap, gas tube, etc.), the switch is closed when overvoltage causes SPD to flash; if there is no voltage switching element (voltage limiting SPD), then the rectangular dashed box in Figure 4 can be replaced by an ideal short circuit.
2) Nonlinear current-dependent resistance R(i); the latter is mainly dominated by the field-dependent resistivity of voltage-limiting components (varistors, avalanche diodes, etc.), and is supplemented by the current-dependent arc resistance of voltage switching components; R(i) also Contains the inherent resistance of the SPD conductive path.
3) Inductance L, related to the inherent inductance of the SPD conductive path and the similar inductive behavior of the protection components, especially the hole effect when conducting surge current through the varistor.

4) Capacitance C R represents the inherent capacitance of the voltage limiting component; resistance R S determines the minimum resistive leakage current of the voltage switching component; if there is no voltage limiting component (voltage switch SPD), C R can be replaced by an ideal open circuit, and C S, R S should be connected in parallel to R(i) and S(V,t) in series, that is, between B and C'.

Since its establishment in 2006, Jinli Electric has been deeply involved in surge protectors for nearly two decades, adhering to the corporate mission of "creating the world's No. 1 lightning protection brand to protect users from lightning intrusion". Self-developed and produced surge protectors for charging piles, such as JLSP-BC15, are deeply loved and trusted by the majority of users.