Coal Mining and Process Automation
Coal mining is a labor-intensive process that requires high reliability from machinery and mechanisms. Reforms in the mechanization of the coal industry aim to significantly increase profitability and coal production volumes, which can potentially double or triple. Shearer loaders (SL) demonstrate exceptional productivity and operational speed designed for the coal extraction face.
Automation System for Shearer Loaders
Currently, engineers have developed an automation system for shearer loaders that includes a special electric drive with microprocessor control of the motor. This system can provide braking during the descent of the SL using an inverter.
Main Characteristics of the System
This automation system has the following key characteristics:
- Separate shutdown and startup of the SL device.
- Ability to start both from the SL control panel and from a separate control unit operating via radio channel.
- Automatic speed adjustment of the electric motor in cutting mode.
- Automatic control of augers depending on power.
- Self-diagnostic capability of the system with messages displayed on the screen.
Electric Drive Control
The electric drive control of the SL is based on the use of microprocessors that implement software control and diagnostics. Self-diagnostics is one of the most important functions of the device. This function allows for the regulation of the electric motor current, temperature of converter components, and detection of system errors. The main operational parameters of the SL are also monitored by this system.
System Structure
The automation system consists of three microcontrollers: MK1, MK2, and MK3. They are interconnected via a system bus and perform the following functions:
- MK1: The leading controller for the other two, executing automation, startup, and shutdown functions of the combine system.
- MK2: Controls the rotation frequency, drive coordinates, and protects the electric drive from short-circuits and overloads.
- MK3: Constantly monitors and queries information from sensors, providing system diagnostics and preventing the exceedance of permissible parameters (pressure, temperature, current).
In case of exceeding permissible values, MK1 reports this, and the system automatically cuts off the power supply.
Conclusion
All information from the microcontrollers is displayed on the screen, and in case of an error, it is instantly indicated. Such automation systems with electric drives are currently installed on KVP-type combines, significantly enhancing their efficiency.