Numerical Analysis of Breakdown Phenomena for Polymeric Insulators After Thermal Aging Process

We numerically analyzed the changes in breakdown strength after the thermal aged low-density polyethylene employing quantum chemical calculations. The newly generated impurity in the molecular chain produced the new energy states by the thermal aging process. The quantum chemical calculation contributed to analyzing these microscopic changes in energy state. In particular, the increases of deep traps greatly affected the space charge dynamics and breakdown strength. Finally, we numerically analyzed the changes in the deep trap that played an important role in changing the breakdown strength by employing the finite element method.