Analysis of Capacitance Dielectric Loss Factor Under Different Environmental Simulation

This paper addresses the dielectric loss characteristics and aging assessment of metallized polypropylene film capacitors used in vehicle-mounted inverters, proposing a comprehensive research method based on COMSOL multiphysics coupled simulation and frequency-domain dielectric spectroscopy. By constructing a detailed model that interplays electric, thermal, and moisture fields, the nonlinear control mechanisms of dielectric loss factor (tanθ) under temperature, voltage, and humidity gradients are systematically analyzed. Confirms the strong correlation between the rate of dielectric loss factor change and capacitor performance degradation, with the tanδ value (1 kHz) increasing from 0.004 to 0.012 after aging, resulting in a 30% decrease in energy storage efficiency. This study innovatively proposes a multi-scale modeling approach that considers interface polarization effects, achieving precise alignment between simulation and experimental data through bidirectional verification mechanisms (root mean square error <3%), revealing the nonlinear response of space charge polarization triggered by localized field strength concentration (12 kV/ mm).