With the rapid development of flexible DC transmission technology

large-capacity metallized film capacitor

as one of the important supporting devices

undergoes rapid changes in port currents during wide-frequency transient processes such as continuous charging and discharging. This leads to uneven current distribution inside the capacitor

which affects the multi-physics field distribution and stable operation. We analyzed the frequency range of metallized film capacitors for flexible DC transmission applications

and introduced the major research advances in capacitor wideband calculation models

internal multi-physical field distributions (electric field

temperature

and stress)

and the effects of current surges on capacitor performance. It is found that the development of well-performing capacitors requires not only the improvement of material properties but also attention to capacitor analysis and design techniques. Finally

an outlook on key technologies to enhance the performance of capacitors was presented from both design and application perspectives.