Application of Frequency Converters for Gravel Dredging with Floating Grab and Bucket Chain Dredges

摘要

Besides the slip-ring induction motor, the direct current drive has found widespread application for many years as driving system for hoisting gear of floating grab dredges. The development of vector control (field-oriented control) for frequency converters, however, is now leading to a replacement of these drive systems. In combination with the virtually maintenance-free three-phase current squirrel-cage induction motors of high protective type (IP55), the advantages of the direct current motor can be used without have to accept its disadvantages. Besides the considerably lower maintenance costs compared to hydraulic drives and also environmental protection as one of the most urgent problems of our age - the question of a driving system also plays a significant role for bucket chain dredges. Here the frequency converter also offers an option which will become widespread on a medium-term basis.