Effect of SiC diodes on power losses of the voltage-source shunt active power filter

A major drawback of the silicon (Si) diodes used in power electronic applications is the high reverse recovery current causing high switching losses which constitute a significant proportion of the total power losses in the pulse-width-modulated semiconductor bridge. An attractive alternative to the silicon diodes are Schottky barrier diodes fabricated in silicon carbide (SiC). SiC diodes offer several benefits, such as greatly reduced switching loss and higher junction temperature over their silicon counterparts. This paper studies the use of silicon carbide Schottky diodes in the voltage-source shunt active power filter. The Si diodes of the conventional three-phase bridge are replaced with their SiC counterparts to determine their effect on the semiconductor bridge power losses. The power losses are first determined by calculations and the distribution between the conduction and switching losses is estimated Finally, measurements are performed to verify the results. The results show that by using SiC components examined the semiconductor losses are decreased about 20%. Copyright (C) 2007 Praise Worthy Prize S.r.l. - All rights reserved.