VVVF device communicates with monitoring device by Profibus-DP, which can achieve fast control and monitoring device running status; meanwhile, it reduces the cable laying and makes the operation and maintenance convenient. PLC communicates with Industrial Personal Computer by Ethernet, real-time monitoring complete set running status and feedback with latest fault information.

The ship is installed with GPS, safety monitoring alarm device, cabin monitoring device and CMS etc.

Electrical control system of gantry crane for ship building

The gantry crane is main equipment for ship assembly in the shipbuilding plant. The equipment can hoist various sections, translate, rotate and precise position. It can hold the weight for a long time when ship segments are weld and assembled.

The gantry crane body consists of a rigid leg, a flexible leg and a horizontal beam. The connection between the rigid leg and the horizontal beam is fixed. The connection between the flexible leg and the horizontal beam uses seat hinge. Upper cart mechanism and lower cart mechanism are set on the horizontal beam. The upper cart has 2 main hoisting mechanisms. The lower cart has 1 main hoisting mechanism and 1 secondary hoisting mechanism. The carrier travels on the track along the dock.

The main hoisting mechanisms can run individually, or run synchronously 2 or 3 together. The 2 carts can run individually or synchronously.

Electrical system solution

ABB DTC variable frequency speed control technics

Hoisting macro is applied to enhance hoisting function and safety.

The motor math model can be setup conveniently and precisely by motor ID identification and magnetic flux optimization

Achieve the accurate speed and moment control at constant moment section and constant power section of standard squirrel-cage motor with pulse encoder feedback

OMRON CS1-H large PLC control and CMS system

Complete zero protection, sudden halt protection, weight limitation and overspeed protection etc.

Main control function

Hoisting mechanism is allowed field-weaking speed increasing running at 40% rated load

Hoisting hook synchronizing precision control ±40mm when speed is stable

Upper and lower cart synchronizing precision control ±20mm when speed is stable

Manual and auto rectification devices are used for the carrier running

Sensors are set at regular intervals along the carrier track to check the pulse encoders on the both side of rigid and flexible leg

The deviation is lower than specified value when the carrier startup and brakes. During the running:

When the difference achieves deviation range 1, sound and light alarm and auto rectification are performed

When the difference achieves deviation range 2, the carrier reduces speed automatically; sound and light alarm and auto rectification are performed

When the difference higher than deviation range 3, rectify manually