Equivalent accelerated aging method to evaluate long-term performance of metalized film capacitor for voltage source converter application

Metalized film capacitor (MFC) with ultrahigh power is one of the key power devices in High Voltage Direct Current (HVDC) power transmission technology, and the evaluation of its long-term performance (especially its lifetime) is of great importance for reliability of HVDC system. But those experiments require enormous power supply capacity which is difficult to achieve in laboratory. In this paper, we propose a feasible equivalent experiment method to evaluate long-term performance of ultrahigh power MFC, which employs floating aging at elevated temperature and voltage level imitating electric and thermal effect in operating condition. Thermal effect of ripple current has been equalized as temperature rise of 14.7°C according to finite element analysis and temperature rise experiment, and the enhanced strength of electric field caused by the ripple voltage has been equalized as voltage rise of 196V. The equivalent method proposed enables laboratory study on long-term performance of ultrahigh power MFC.