Design of protected circuit models for nonlinear dielectric conductivity measurement system under high-energy impulse breakdown conditions

During high voltage tests for nonlinear dielectric samples, accidental breakdown may occur due to the influence of some objective factors (such as material defectiveness, ambient temperature, air humidity, etc.). Under the high voltage conditions, a high energy impulse causes breakdown discharge resulting in test equipment failure. In this article, several unique types of LC and RC filtering circuit models are proposed to protect the nonlinear dielectric conductivity measurement system. Simulation of the proposed design models are carried out using “MATLAB Simulink”. The simulation results revealed that all LC and RC filtering circuit models have a protective function for the test equipment, and can buffer the voltage-raising amplitude. By comparison, it is observed that the LC filtering circuit model has a better buffer-function than RC filtering circuit model. The LC filtering circuit can make the voltage-output curve more lenitive, and significantly increase the safety of measurement system. In addition, the comparison of single LC/RC and π LC/RC filtering circuit models show that the π LC/RC filtering circuit model has a better buffer function. Furthermore, in the high electric-field breakdown the π LC/RC model can make a less steeper voltage-output curve. The filtering principles of these kinds of filtering circuit models were discussed, and the correctness of simulation results were validated by experiments.