1.introduction
Belt conveyor is an important equipment for coal mining and transportation, due to the different geological conditions in the coal mine, the use of the belt conveyor has lane transportation, upward transportation and downward transportation. Due to the self-weight component of the material and tape in use, the belt will convert the mechanical energy of the downward movement into electrical energy to feed back to the motor and drive equipment. If the energy can be recovered to the power grid, it will be very beneficial to the energy saving and consumption reduction of the coal mine.Therefore, FGI's explosion-proof four-quadrant inverter is applied to the belt conveyor to effectively improve its efficiency.
In the frequency conversion drive of the downgoing belt conveyor, it is not only necessary to solve the power balance of multiple motors, but also to control the energy feedback generated by the downgoing belt conveyor, so the frequency conversion drive of the downgoing belt conveyor is more complicated than that of the down-channeling belt conveyor and the up-going belt conveyor.
2.Problems existing in the application of traditional belt conveyor
The traditional belt conveyor adopts the power frequency operation mode, due to the long-term power frequency operation of the motor, coupled with the efficiency of the hydraulic coupler and other problems, the belt conveyor is very uneconomical to run.
Because the motor can not use soft start, soft stop, produce severe impact on the machinery, accelerate the wear of the machinery.
Belt, hydraulic coupler wear and maintenance problems will bring a large amount of costs to the enterprise.
The application scenario of the conveyor belt cannot achieve energy feedback, resulting in a waste of electrical energy.
3.FGI explosion-proof four-quadrant frequency inverter
FGI explosion-proof four-image inverter rectifier and inverter adopt three-level topology, the use of low-voltage power devices to achieve medium-voltage inverter output, high reliability.
Power factor up to 1, to achieve green frequency conversion.
FGI explosion-proof four-image inverter adopts 485 and CAN communication to achieve master-slave control.
The power input of FGI explosion-proof four-image inverter adopts a wide power grid design of 970V~1310V, which can meet the harsh power grid environment of the mine.
Direct water supply heat dissipation, the process is simple and maintenance-free.
4.FGI explosion-proof four-image inverter efficiency
FGI explosion-proof four-quadrant frequency inverter speed synchronization, current balance. Slave output torque is the same as that of host. The current difference displayed on the interface is less than 1%. The slave machine does not match the speed of the main machine, resulting in overvoltage and overcurrent phenomenon.
FGI explosion-proof four-quadrant inverter has excellent soft start/stop characteristics. Acceleration/deceleration time (0-60min) is continuously adjustable, and can achieve S-type acceleration and deceleration, effectively reducing start-stop impact.
FGI explosion-proof four-quadrant frequency inverter heavy load starts smoothly. The belt conveyor stops and restarts at any time in the coal transport process without problems, and the low-frequency operation can output up to 2 times the rated torque.
FGI explosion-proof four-quadrant inverter using PWM rectification technology, the motor renewable energy into electrical energy back to the grid, the power factor can reach more than 0.98, the maximum energy saving.
