Mine winches are key equipment in mining production. They are responsible for personnel lifting and lowering, and material and equipment transportation. They are called the "throat of the mine". Their operational reliability, safety, and economy have attracted much attention. This article introduces the application of FRECON Electric's FR500A inverter in a company's mine winches. The original system used a winding asynchronous motor rotor circuit with a series resistor for speed regulation. After being upgraded with the FR500A inverter, the failure rate was reduced, electricity was saved, and production efficiency was improved.
Core components of mine winch structure:
The transmission system has main shaft device, cathead shaft, etc., and some are three-axis transmission;
The braking system is equipped with disc brake, etc., which is controlled by hydraulic pressure;
The power system is driven by flameproof motor, which is transmitted to friction wheel or drum through reduction box, etc.;
The control system uses tooth clutch and other parameters for adjustment; the safety device includes depth indicator, etc. Different models are adjusted according to the purpose, such as the dispatching winch has a seat and a protective cover.
The mine winch uses the motor as the power source, and transmits the torque to the drum through the reduction box and transmission gear to drive the wire rope to wind or release. The motor speed is adjusted by the inverter to achieve precise speed regulation and smooth start and stop. The braking system (disc brake/hydraulic brake) applies braking force in shutdown or emergency situations to ensure safety. The depth indicator and protection device monitor the operating status in real time to prevent accidents such as overwinding and overspeeding, and ensure reliable lifting operations.
The upgrade system consists of a inverter, PLC, contactor, brake unit, brake resistor, etc. After the equipment is installed, the control circuit is powered on, but the main circuit is not powered on, and the control circuit and PLC program are debugged to ensure that the logic control is correct and the components operate normally.
No-load operation: The motor is disconnected from the reducer, and the inverter uses V/F control mode to run no-load, ensuring that the motor runs stably and the inverter output voltage and current are normal.
Self-learning: Use PG-free vector control to perform rotary self-learning to obtain motor parameters, then run the motor at no load and adjust the parameters to ensure stable motor operation.
Running with load: The motor is connected to the reducer, and the inverter uses PG-free vector control to run with load to ensure stable operation of the motor.
System coordination: ensure that the mine winch can lift and lower with no load or heavy load, the speed of each gear meets the requirements, the gear shifting is normal, the inverter and PLC system operate normally, and carry out the industrial and variable frequency switching test.
High energy consumption: The rotor is connected to a resistor in series with the speed regulator, and the slip power is completely consumed by the resistor, with an efficiency of only 60%-70%;
High maintenance cost: The contactor, brushes, and slip rings need to be replaced frequently, the brake pads wear quickly, and the annual maintenance fee increases by 30%;
Poor speed regulation performance: Stepped speed regulation leads to soft mechanical characteristics, the output torque drops by 40% at low speed, the operating impact is large, and the failure rate is high;
Low reliability: The contact points of the contactor are prone to sintering, and the lack of protection leads to a motor burnout rate of 5%/year.
Excellent speed regulation performance: adopting PG-free vector control, starting torque reaches 200% rated value, mechanical characteristic hardness is increased by 50%, and positioning accuracy is ±1mm;
Smooth operation and low consumption: smooth speed regulation reduces mechanical shock, the life of the reducer is extended by 2 times, and the system efficiency is increased to 95%;
Simplified maintenance: the winding motor is changed to squirrel cage type, maintenance-free brushes/slip rings, and the annual downtime is reduced by 80%;
Comprehensive protection function: integrated overcurrent, overvoltage, phase loss, overtemperature and other 12 types of protection, fault self-diagnosis accuracy rate is 99%;
Significant energy saving: after removing the speed regulating resistor, the annual power saving reaches 300,000 kWh (based on 100kW winch), and the investment recovery period is less than 2 years.
Core value: FR500A inverter solves the pain points of "high consumption, low efficiency, and difficult maintenance" of traditional systems through software and hardware collaborative optimization, and realizes safe, stable and economical operation.
