| 摘要 |
PROBLEM TO BE SOLVED: To reduce the higher harmonic current generated in converting the AC current into the DC current by a rectifier by providing a DC generator to feed the common DC power supply to an inverter device to feed the AC power supply to each motor such as those for traveling, hoisting, level luffing, and slewing. SOLUTION: An inverter device 5A for traveling of a jib crane, an inverter device 5B for hoisting, an inverter device 5C for level luffing, and an inverter device 5D for slewing are connected in parallel, and the AC power is supplied to motors 9A, 9B, 9C, 9D corresponding thereto. A DC generator 2 to feed the DC power supply to the inverter devices 5A, 5B, 5C, 5D is connected in parallel. The DC main circuit current is directly inputted to an inverter control device from the DC generator 2, and the harmonics generated from a rectifier can be reduced. |
