Experiment and Simulation on Dynamic Conduction Characteristics of Carbon-Ceramic Closing Resistors in Circuit Breakers Under Impact Energy Injection

As a critical energy-absorbing component in ultra-high voltage circuit breakers, carbon-ceramic closing resistors experience frequent failures under high-energy transient impacts, and the dynamic resistance stability under large energy injection determines their energy tolerance threshold. In this study, experiments on the impact energy of carbon-ceramic closing resistors and simulations of the microstructure conduction model were carried out to obtain the dynamic conduction characteristics of resistors. The microscopic conduction mechanism of carbon-ceramic resistors during impact energy injection was revealed from the perspective of voltage and temperature regulation. The study indicated that (1) under impact energy injection, the resistance value of the carbon-ceramic resistors undergoes a dynamic variation process, which starts with a sudden drop, followed by a rapid decrease, then small-range fluctuations, and finally a slow increase. As the pulsed voltage increases, the resistance of the sample at the peak moment and the minimum resistance both decreased. The minimum reduction rate increases from 16.80 to 26.89%, while the time required for the dynamic resistance to drop to the minimum value extends from 2.25 to 7.61 ms. (2) By simulating the tunneling effect regulated by voltage and the contact resistance change controlled by temperature, it was verified that the dynamic changes in voltage and temperature under impact energy injection are the reason for the resistor's dynamic conduction characteristics.