Experimental Study on Performance of Submodule Capacitor in Unified Power Flow Controller

Metallized film capacitors have the advantages of high energy density and high reliability. However, there is no research on the characteristics of metallized film capacitors in UPFC modular multilevel converter. Therefore, this paper takes UPFC sub module capacitor as an example. First, the operation of UPFC submodule capacitor is studied. Operation characteristics are extracted. Then the breakdown characteristic and temperature rise characteristic test platform is designed, and the breakdown characteristic and temperature rise characteristic test under different power supply characteristics are carried out. Finally, the results are summarized. The results show that the DC voltage amplitude, AC voltage amplitude and frequency have little influence on the average breakdown voltage of metallized film capacitor and has a rapid thermal balance without external heat dissipation.