Beijing subway construction-2018-01-15

It was expected to open in 2020. On this subway line, there are 20 stations and 9 transfer stations. The Middle East bridge station and future technology city station are the two most special ones for V&T. As a result, the electric automatic control system of bridge grab crane designed by V&T and zhongchuang minghui company has been successfully applied in east daqiao station and future science and technology city station, and has been well received by customers.

Grab crane

Grab crane refers to the grab crane, was a kind of automatic fetching machinery, its grab and unloading material action was controlled by the ship unloader driver, do not need auxiliary personnel, thus avoid the heavy labor of workers, improve the efficiency of loading and unloading. Bridge grab crane for bulk and granular materials, mainly used in grasping soil and coal and other occasions.

Grab crane electrical system

The electric control system of the bridge grab crane, the control of the opening and closing of the grab elevator was firstly sent to the PLC by the operation console, and then the PLC comprehensively judges according to the parameters of the current, torque and speed of the two motors. The control inverter gives the optimal relative running speed and torque, ensuring that there was no scene such as rolling, spreading, etc., achieving fast, accurate and efficient semi-automatic operation of the grab. When the human was mwashandled, it may cause the grab to open when lifting. At this time, no human correction was required, and the low speed 1 and 2 gears are normally lifted, the grab will gradually close itself, and the normal speed can be operated at the highest speed after ten seconds, greatly reducing the operator's work intensity and the operator's operational skills and responsibilities. The heart requirements are also greatly reduced.

When the grab machine was running tens of meters away from the ground, it was difficult for the operator to see the situation of the grab. If the grab machine was not intelligent, the operator's work efficiency will be very low. The V&T intelligent grab machine system perfectly solves this problem, which fully improves the operator's work efficiency. The most important thing was that the operator's technical level requirements are greatly reduced, and work can be done without experience.

The speed of the grab elevator opening and closing was divided into 3 grade. The auxiliary hook, cart and trolley motor are directly controlled by the operation console, and the speed was 4 grade. The speed changes smoothly, the operation was stable, the low speed performance was stable, and the starting current was small. Even with frequent start and stop, the heat consumption of the motor was reduced, extending the life of the motor. The main frequency drive and the large and small frequency drive adopt the DC common bus method to reduce the number of cabinets used, thereby reducing the customer procurement cost.

Each inverter communicates with the PLC through 485 communication mode. The PLC connects to the touch screen through 485 communication mode. The status and operation data of the system are dwasplayed on the touch screen. Some control parameters can also be modified on the touch screen.

With its superior soft start and smooth speed performance and perfect protection function, the inverter can provide favorable conditions for the reliable operation of the “bridge grab” drive system. The PLC control inverter control scheme can make the crane speed control safer. Accurate and effective, the most important thing was that the operator can see all the control status of the system from the touch screen. When the system goes wrong, the maintenance technician can directly see the fault point, including the specific fault information of the inverter, so that the problem can be quickly eliminated.

As a domestically experienced and efficient inverter R&D, testing, production and marketing team, and its successful application of the bridge-type grab crane electrical automation control system designed by Zhongchuang Minghui Company. It shows that V&T's products are indeed very reassuring in the special field, and the pride of the domestically produced inverter brand.