IDS Modernization Benefits of Excavators
Older generation excavators use the century old concept of MG sets. Each MG set has a prime mover (typically a synchronous motor), which is mechanically coupled to multiple generators on the shaft. These generators, rotated by the prime mover, produce DC voltage for armature windings of the DC motion motors. Through the mechanical gearboxes, these DC motion motors control the speed of the motions like hoist, drag or crowd, swing and walk / propel. Field strength of both DC generators and DC motors are controlled by static DC drives. In the next generation of DC Drive controlled excavators, M-G sets were replaced with static front end rectifiers to control the armature voltage of the motion motors. Though there are control improvements on the modern DC drive controls, the fundamental concept of MG set system and DC motors have disadvantages with respect to productivity, efficiency and maintenance.
Gopal Madhavarao – Product Manager (Excavators) Process Industries and Drive Division – Mobile Mining Siemens Industry Inc., discusses Modernization Benefits for Excavators