Dears,

for steel rolling mill application, what is more energy efficient system ?? 

1- DC Motor + SINAMICS DCM Drive 

2- AC Induction Motor 690V + SINAMICS S120 including smart line module

Thank you in advance

Mohammad Abusharkh 

Check DC motor & AC motor efficiency. DC motor additional blower energy cost & maintenance cost is more as compare to AC motor energy & maintenance cost. In Sinamics you can activate energy saving feature which is not case with DC drive. (refer below example)

SINAMICS S120 Chassis low-voltage converters, water cooling for a common, cooling circuit – release for sale: Active Line Modules, Active Interface Modules and Motor Modules

Low voltage converters SINAMICS S120 liquid-cooled – Sales and delivery release: Active Line Modules and Motor Modules

Low-voltage converters SINAMICS S120 Liquid-cooled Chassis – Sales release: Active Line Modules and Motor Modules