Frequency Converter Crane
Advantages of Frequency Converter in Crane Industry
First, the system overview:
Gantry crane, widely used in indoor and outdoor warehouses, factories, terminals and open storage yard, etc., is a lifting industry, a typical equipment. General system has improved, cart, car three kinds of technology need to control. Now can be used to achieve frequency conversion. Which the hoist on the inverter requirements of the highest, up and down can not produce “slip hook” phenomenon, the performance of zero speed need to output at least 150% of the rated torque; function on the need to have a reliable brake timing control. Large, car sharing a converter control, to achieve two sets of parameter identification and switching. To reduce the overall cost of equipment.
According to the above characteristics, I developed a special software, hardware, configuration in the CHV180 series of products. To achieve precise control of the crane.
For the lifting machinery, the use of closed-loop vector control, increase the brake control function. Effective to achieve no slip hook; set S curve acceleration and deceleration mode, to ensure the stability of the lifting process. For the size of the single car inverter switching control, in addition to enhance the performance of the mechanical function, but also increase the special features, a single inverter can identify multiple motors, the use of parallel way. At the same time a single inverter control two sets of motors, which group of motors need to control the operation, the inverter automatically switch to which set of motor parameters.
- Reliable brake logic control, while the brake time adjustable, in ensuring that the hook is not at the same time, but also to avoid the motor’s large current shock. 2. High-performance closed-loop vector control, at zero speed can output 180% of the rated torque up to 10S. Increased system reliability.
- Acceleration and deceleration in accordance with the S curve mode, increasing the stability of the work, reducing the mechanical impact. Extend equipment life.
- When the motor is connected in parallel, the inverter automatically recognizes the parameters and establishes an effective mathematical model. Control accuracy is very high.
- Single inverter switching control of two groups of motors, automatic identification and storage of two sets of motor parameters. Reducing the cost of the machine, greatly improving the competitiveness of the machine.
- Adjustable torque compensation for precise control.
Second, the control principle:
The main lifting motor is controlled by a single inverter, and the vector is closed-loop, in which the brake control signal is sent to the PLC control cabinet by the inverter, and the control cabinet receives the signal and controls the loosening of the brake. Lift the inverter external braking unit DBU (matching dynamic resistance) or feedback unit RBU, directly to the energy feedback to the grid. The system uses DBU.