Veichi QT series tower crane control system has specially developed with modular design: the lifting, slewing and luffing control module run independently without interference. Besides, it has been integrated with smart PLC and IOT control unit.
A. Lifting control unit:
a. It adopts open loop vector control, closed loop vector control and V/F control mode.
b. It is capable of running for a long time, braking at zero speed and running smoothly without shaking. By using QT series, it extends the service life of tower crane's components such as transmission mechanism, steel wire rope and more parts. Meanwhile, it effectively improves the safety of tower crane.
c. Strong adaptability to power grid: at low voltage, it can maintain constant output torque.
d. Improved working efficiency: automatically start high speed status when the crane is in light load.
e. Developed with dedicated brake logic timing control and dual redundant brake control, it is more safe and reliable.
f. In closed loop mode, it has stall protection function, zero servo hovering function and anti-slip hook subsidiary protection, so it makes tower crane work with improved reliability.
B. Slewing control unit:
a. QT125 tower crane inverter adopts flexible torque control that it features powerful jog, fast response, steady running without rebound.
b. It can adapt to various kinds of motor control such as vortex motor rigid connection, the fluid coupling soft connection and torque motor rigid connection.
c. The built-in vortex controller adopts PWM pulse width modulation that it can adjust the output voltage in real time according to the running frequency. Comparing with conventional eddy current voltage regulator module, it is of more outstanding performance.
d. It makes the gear convert stably and fluently without pause phenomenon.
C. Luffing unit:
Developed with anti-swing function, it makes easy in hooking.
D. PLC ogic control unit:
a. Multiple input and output interfaces; 39 digital value, 4 RS485 communication interfaces, 10 analog value, 1 black box interface, 8 collector outputs, 1 eddy current output, 2 brake outputs.
b. Safety: the safety can be better guaranteed due to the dual interlock of logic software and hardware in brake circuits.
c. There are clear instructions for various limits and master signals, which is extremely convenient for installation and maintenance while reducing equipment maintenance costs.
E. IOT remote control unit:
a. Through remote monitoring module, it can achieve online monitoring and remote fault diagnosis.
b. Remotely monitor the tower crane to check whether it’s overweight, illegally operated and more in order to prevent accidents from happening.
It includes overweight, super torque, spacing limit, over current, overvoltage, under voltage, loss phase, short circuit protection and more protection functions.
QT series have been designed with clear LED indication and silkscreen in all the main order, spacing limit, emergency stop, and safe feedback signals and etc. It is very easy for engineers to operate and maintain. Besides, it is of outdoor waterproof design with IP25 protection class.