Abstract:

Mine hoist is one of the significant safety equipment in mining, playing a crucial role throughout the production process. Therefore, the safe and reliable operation of the equipment is particularly important. In the past, there were many deficiencies in the equipment, and the addition of the frequency inverter will effectively address these shortcomings.

Overview of Mine Hoist Frequency Speed Regulation

Frequency regulation, with advantages such as smooth speed control, a wide speed range, and energy-saving, has been widely applied in mine hoists. The following requirements are generally placed on the frequency inverter for mine hoists:

1. The mining power grid fluctuates significantly, and the inverter should work normally within 380V±20%.

2. Smooth operation with smooth acceleration and deceleration, achieving continuous acceleration without impact during acceleration and deceleration.

3. Handling of feedback energy: feedback braking or energy consumption braking.

4. The inverter should provide the required torque characteristics throughout the working process: the starting torque is greater than 2 times the rated torque, especially when the mine car is stopped in the middle of the shaft, the starting torque is much greater than the rated torque.

5. Sufficient acceleration torque to adapt to the acceleration process during heavy load lifting.

6. The inverter should withstand torque jumps caused by uneven track or occasional wire rope twisting during operation.

7. In case of occasional events during operation, rapid braking is required to provide braking torque greater than the rated torque. This will result in a significant energy feed to the inverter.

8. In the stopped state, the inverter should provide braking torque greater than the rated torque to prevent the heavy load from slipping.

Application Solution for Frequency Speed Regulation

The hoist used this time is the TKD single-rope winding mine hoist. The original system configuration includes a 2m drum, a single-hook type, the mine is a inclined shaft with a depth of 100m, and the lifting weight is 10 tons. The motor is a 380V/200KW/8-level wound rotor three-phase asynchronous motor with a motor reduction ratio of 20, and the braking method is a hydraulic station disc brake. The inverter is 250KW, and the customer provides the braking resistor for the braking unit.