I am wondering if the application only required to convert the grid frequency of 50Hz to 60Hz for ship shore supply, is it still required to use the AFE converter to power a DC bus with battery bank, and then convert back using a second AFE converter for 60 Hz requirement?
Song Keat Eng You can use 6 pulse or 12 pulse but to maintain a high enough mindex (modulation index) the dc voltage produced must be high, typical way above 650 vdc under load. This require a special trafo in front with output above 500 vac. With an AFE the dc boosting can easily produce 750 vdc from standard 400 or 440 vac. Easy to maintain mindex and also achieve highest VA performance. Grid converters are "dc voltage junkies".
I am wondering if the application only required to convert the grid frequency of 50Hz to 60Hz for ship shore supply, is it still required to use the AFE converter to power a DC bus with battery bank, and then convert back using a second AFE converter for 60 Hz requirement?
Song Keat Eng You can use 6 pulse or 12 pulse but to maintain a high enough mindex (modulation index) the dc voltage produced must be high, typical way above 650 vdc under load. This require a special trafo in front with output above 500 vac. With an AFE the dc boosting can easily produce 750 vdc from standard 400 or 440 vac. Easy to maintain mindex and also achieve highest VA performance. Grid converters are "dc voltage junkies".
Thanks Reidar! It is very helpful!