The FGI FD5000 medium-voltage frequency converter solves the problem of heavy-load and long-distance transportation
At a time of energy transformation and development, coal is a key basic energy source in China. Its efficient and environmentally friendly transportation and utilization are of vital importance for ensuring energy supply and promoting sustainable economic development.
The Zhundong Coal and Electricity Base in Xinjiang is an important coal-producing area in China. It relies on the ± 1,100-kilovolt ultra-high voltage direct current transmission project from Zhundong to East China (the fourth channel of "Xinjiang Electricity Transmission to Other Regions") to achieve power transmission to other regions. Dozens of large thermal power plants around it provide regional power supply and Xinjiang electricity transmission to other regions. However, at present, the transportation from coal-producing areas to power plants is mainly by road, which has high logistics costs and is greatly affected by the climate. Under extreme weather conditions, the transportation efficiency and stability are not good. To address this issue, achieve efficient and environmentally friendly coal transportation, reduce costs and increase efficiency, and enhance the reliability of energy transmission, it is imperative to build a long-distance coal conveying system from coal mines to power plants.
1.Project requirement
The newly built belt conveyor line has a total length of approximately 45 kilometers, with a belt width of B = 1200mm and a system transportation capacity of Q = 800t/h. This line is composed of a total of 7 belt conveyors, namely 300, 301, 302, 303, 304, 305 and 306. The drive configuration of each conveyor is as follows:
The three belt conveyors, 300, 305 and 306, are respectively equipped with one low-voltage permanent magnet synchronous motor and one low-voltage frequency converter, and adopt single-drive mode. 301 belt conveyor length about 5 km, USES the head double displacement method, form a complete set of two high voltage permanent magnet synchronous motors and two high voltage frequency converter. 302, 303, 304 three belt conveyor length is about 13 km, driven by the first two tail a way, form a complete set of three high voltage permanent magnet synchronous motor and three high voltage frequency converter.
Due to the long route of this project, which crosses highways and railways, traverses complex areas such as deserts and slopes, and has a large temperature difference (-30℃ to 40℃), extremely high requirements are placed on the stability of the inverter drive operation. The specific requirements are as follows:
(1) synchronous control
The frequency converter is required to have a synchronous control function to avoid belt tension imbalance caused by uneven power distribution and ensure the stable operation of the conveying system.
(2) high starting torque
Long-distance conveyors have large load inertia and require frequency converters to provide high starting torque at low speeds (usually above 150% of the rated torque) to prevent belt slippage or mechanical shock and ensure the safe start-up of the equipment.
(3) Reduce speed and stop
The shutdown mode requires deceleration and stopping. Long-distance belt conveyors have large loads and inertia. Sudden power cut-off and free shutdown may cause the belt to continue sliding, resulting in material accumulation, belt deviation, and even mechanical damage. Even in emergency situations, free shutdown cannot effectively control the shutdown process, posing safety hazards. Deceleration and shutdown can smoothly reduce the speed, minimize mechanical shock, protect the equipment, and at the same time prevent material spillage, thereby enhancing safety.
2.FGI solution
In response to the customer's demand for long-distance belt conveyor systems, FGI has meticulously designed an appropriate solution to meet the requirements of power balance among multiple machine drives, large starting torque, and safety and stability. FGI recommends the FD5000 high-voltage inverter and FD100 low-voltage frequency inverter for the customer to adapt to the drive of 7 belt conveyors on site.
The specific plan is as follows:
The 300 belt conveyor, 305 belt conveyor, and 306 belt conveyor are all equipped with FGI's FD100 low-voltage inverter for individual drive.
The 301 belt conveyor is equipped with the Inverter FD5000 series medium voltage drive from Yideng for dual drive at the head. The master-slave communication is achieved through a single-core 15-meter ST type multimode optical fiber connected in a hand-holding ring configuration.
302, 303, and 304 belt conveyors are driven by two motors at the head and one at the tail. The signals are transmitted through optical fibers to ensure reliable communication. The FD5000 inverter ensures balanced motor power, synchronization, and enables real-time communication with the PLC.
3. Customer benefits
Energy conservation and reduction of consumption, as well as lowering operating costs
The frequency converter supports continuous adjustment of speed from 0% to 100%, meeting the requirements of different working conditions (such as low-speed operation during maintenance and high-speed transportation during peak hours). It fully meets the two speed modes of on-site belt inspection speed and full-speed operation, reducing unnecessary energy consumption.
Soft start and soft shutdown, extending equipment lifespan
Eliminate mechanical shock: The frequency converter controls the start-up and shutdown process through a smooth S-shaped acceleration and deceleration curve, avoiding shock during startup and reducing the wear of mechanical components such as belts and drums.
Controllable shutdown protection: Deceleration shutdown (instead of free shutdown) can maintain stable belt tension and prevent belt slackening, slipping or material accumulation due to inertial shock.
Improve control accuracy and operational stability
Heavy-load start with large torque, the IF program can meet the problem of emergency stop and restart of the belt conveyor in heavy-load conditions on-site, solving the industry's problems of synchronous machine's difficulty in starting under heavy load, vibration and easy reversal, ensuring the successful one-time start of the equipment under heavy load; when multiple motors are synchronized controlled, the frequency converter realizes torque/velocity synchronization of multiple drive points through master-slave optical fiber communication, solving the problem of uneven power distribution caused by scattered drive points in ultra-long-distance conveyors.
Intelligentization and remote management
The frequency converter and PLC use modbus 485 communication, which can collect real-time data such as input voltage, output current, output voltage, torque, power, transformer temperature, and various signal states. These data are uploaded to the central control platform through the industrial internet for remote monitoring.
The successful application of the FD5000 series high-voltage frequency converter on multi-drive permanent magnet synchronous belt conveyors fully demonstrates its unique control concept and technical advantages. This solution effectively addresses the problems of easy loss of step, vibration and reverse rotation during heavy-load start-up of synchronous machines in the industry. Under the condition of a long-distance distance of 13 kilometers between the head frequency conversion and the tail frequency conversion, it achieves reliable and stable long-distance transmission of control signals, comprehensively tests the adaptability of the long-distance master-slave control scheme software of the frequency converter, and has been highly recognized by the customer.
In the future, FGI will continue to adhere to the concept of deeply exploring industry application technologies. Relying on its complete high, medium and low voltage product lines, strong technical strength and stable product performance, it will join hands with more strategic partners in the industry to make more efforts for the construction of smart mines and promote the development of the energy industry towards a more efficient, intelligent and environmentally friendly direction.
