Main features of Canworld lift-dedicated VFDs
Problems of control system of old-fashioned wiring program:
- Excess inrush current on starting and gear shifting. The starting current is generally 2 - 3 times as much as the rated one. And in case of fast acceleration, the inrush current will even give rise to trip of the main switch.
- Discontinuous gear and speed regulation, leading to great mechanical vibration during operation, which will impact the lifting mechanism and result in unsafe braking.
- A lot of electrical energy is consumed by the resistors during speed regulation, which is such a waste and causes heavy noise and a harsh working environment.
- In case of applications requiring a 24-hour operation, where the production load is quite heavy, the outdated design and manufacturing process of the control system of the wiring program will lead to an awful lot of repair work, causing loss to an enterprise.
With VFDs, the entire system will be improved as follows:
- Small starting current, which falls within a safe range and will not impact the lifting system and the grid.
- Steady running, smooth acceleration and deceleration, and supporting S-curve acceleration, which makes continuous acceleration possible during acceleration and deceleration without any impact.
- Great starting torque for a startup of a suspended weight from any position.
- Sufficient acceleration torque, adaptive to the acceleration of a heavy lifting.
- Strong low-frequency torque, which eliminates the possibility of car sliding.
- Reliable time sequence control logic for braking and brake releasing.
- The CDE500 is provided with more than 50 protection functions. In case of a failure, the PLC will be notified immediately to brake, ensuring the operation safety and stability of the system.
- Variable frequency speed control is continuous speed regulation. Its flexible control greatly improves the performance and prolongs the service life of the system, reduces the maintenance cost and hence increases the profitability of the enterprise.
Braking logic of CDE500 VFDs:
- The VFD receives the running command and starts to output.
- If the output current is larger than “brake release current (EA.02)” and the output frequency reaches “brake release frequency (EA.01)”, and the two aforesaid conditions have been met and lasted for “brake release delay time (EA.03)”, the analog output terminals under the function of “40: brake control” gives an OFF signal to release the brake.
- In case the VFD is running at a constant speed under the set frequency of EA.01, when the running time has reached the set value of “stopping time of acceleration with the brake released (EA.04)”, it will accelerate to the set frequency.
- The VFD receives the shutdown command and decelerates to “brake actuation frequency (EA.05)”, and then run at a constant speed under this frequency.
- When the delay reaches the set value of “waiting time for output signal of brake actuation (EA.06)”, the analog output terminals under the function of “40: brake control” gives an ON signal to actuate the brake; and when the delay reaches the set value of “waiting time for shutdown with the brake actuated (EA.07)”, the VFD will block the output and shut down.、
![康元电气CDE500变频器矿井提升应用案例]( "康元电气CDE500变频器矿井提升应用案例")
This type of hoisting VFDs have been used in the gold mine of Juefa Mining in Altay District, Xinjiang:
• The system is provided with a 2 m roller with a single hook;
• The mine is a vertical shaft with a depth of 500 m. The weight to be lifted is 8 tons.
• The motor is a three-phase asynchronous motor of 380 V/280 kW with a level 6 wound rotor.
• A planet gear reduction drive with a reduction ratio of 30.
• PLCs with a touchscreen control system configured by the user.
• Hydraulic station braking units configured by the user.
• Canworld CDE500-4T355G VFDs.
• This variable-frequency speed regulation system for mine lifting comprises of a console, variable-frequency system, hydraulic station, safety protection and control monitoring system.
Working principles of the lifting system:
- The operator hears the start-up signal and operates the stick to Upward (or Downward) direction.
- The command of running forward (or backward) from the numerical input terminals of the PLC built-in VFD is valid.
- Based on the position of the stick, it is fed back to the VFD AI sampling value to alter the output frequency of the VFD.
- After the VFD outputs frequency to the frequency level detection FDT1, the hydraulic station is operated to release half of the brake.
- Continue to push the stick to Upward (or Downward) direction, and after the VFD frequency output reaches the frequency level detection FDT2, the hydraulic station is operated to release full of the brake.
- The brake is released in two times to effectively ensure the safety and comfort of the lifting system.
- In order to take full advantage of the motor control features of CDE500 VFDs, please set parameters for the motor before you carry out parameter self-adjustment for the motor.
List of parameters configured on the site:
![康元电气CDE500变频器矿井提升应用案例]( "康元电气CDE500变频器矿井提升应用案例")
![康元电气CDE500变频器矿井提升应用案例]( "康元电气CDE500变频器矿井提升应用案例")
Range of voltage level:
220 V (208 V - 240 V)
380 V (264 V - 480 V)
480 V (380 V - 550 V)
690 V (450 V - 750 V)
1,140 V (800 V - 1,310 V)
Range of power level:
1.5 kW - 1,000 kW, all series.
Temperature:
Temperature range for storage: -25°C - 75°C
Temperature range for running: -10°C - 65°C
Altitude:
Operational when no greater than 1,000 m;
When higher than 1,000 m, for every 100 m higher, the rated conditions shall be tightened by 1%;
When higher than 4,000 m, please consult the vendor.
For further information, please refer to User Manual for CDE500 Series.