Design of Power Supply System under Vector Control for Fixed Bridge Cranes in Parallel Running

When closed loop frequency-modulation technique is adopted for synchronous motor under vector control,fixed bridge cranes could be in parallel operation through Ethernet network.If the mass for heavy or large-piece cargo is less than the rated loading capacity,one set of crane is used in operation.If the mass is less than or equal to double rated loading capacity,two sets of crane must be used in parallel operation.Based on some engineering cases,we introduce the electric driving plan for the parallel-operating cranes,expatiate and determine the methods for calculating electric current,peak current,the capacity and location of the box-type substation,which will provide references for similar projects.