Modified Molecular Chain Displacement Analysis Employing Electro-Mechanical Threshold Energy Condition for Direct...

Area of Science:

• Electrical Engineering
• Materials Science

Background:

• Space charge accumulation in high-voltage direct current (HVDC) polymeric insulators distorts electric fields.
• This distortion degrades the overall breakdown strength of the insulating material.

Purpose of the Study:

• To numerically evaluate space charge distribution and breakdown characteristics in polymeric insulators.
• To investigate the impact of temperature gradients and polarity-reversal voltage on breakdown strength.

Main Methods:

• Utilized the bipolar charge transport (BCT) model for numerical evaluation of space charge distribution.
• Introduced an electro-mechanical threshold energy condition with a modified molecular chain displacement model.
• Analyzed the influence of temperature gradients on breakdown strength under polarity-reversal voltage.

Main Results:

• A temperature gradient accelerates the reduction in breakdown strength during polarity reversal, except at 70°C.
• The energy imbalance induced by polarity reversal decreased breakdown strength by 82%.
• The proposed numerical model accurately predicts breakdown strength variations.

Conclusions:

• The numerical analysis model provides a universal tool for predicting polymeric insulator breakdown strength.
• This model aids in evaluating the electrical performance of polymeric insulators in diverse environments.
• Understanding space charge and temperature effects is crucial for HVDC insulation design.