Coal has always occupied a dominant position in the composition of China's energy consumption, and the huge consumption has driven the continuous rise of coal mining. With the continuous improvement of automation and intelligence of coal production, mine explosion-proof frequency converter and energy-saving drive technology have played a good role in the six major application sites of coal mine underground excavation, mining, transportation, lifting, drainage and connection, which is an important way to achieve energy saving, emission reduction and coal mine intelligence.

1.Overview of the Coal Mine

The construction of Shanxi Xiegou Coal Mine started in February 2007, and the Xiegou Coal Mine Reconstruction and Expansion Project is an important measure for the local implementation of the "Rebuilding a Xishan Coal Power Strategy". The project is developed by an energy limited liability company in Shanxi as a whole, with a design production capacity of 15 million tons/year, and is constructed in two phases, the first phase is 10 million tons/year and the second phase is 5 million tons. The mine is located in Shijitagou, Weijiatan Town, the mine shaft is 22 kilometers long from north to south, 3-4 kilometers wide from east to west, with an area of 88.64 square kilometers, geological reserves of 2.164 billion tons, recoverable reserves of 1.414 billion tons, the main mining of No. 8 and No. 13 coal seams, and the two coal seams are mined and transported separately.

Before the transformation, the customer's equipment has small starting torque, large start-stop impact, large impact on the power grid, scraper conveyor always starts frequently or heavy load, the load changes greatly during operation, and even overloads, resulting in frequent production failures, high maintenance costs, and very affecting production efficiency. Based on the reliable reputation of Cumark high-performance explosion-proof high-voltage inverter series products in the mining industry, the customer entrusted Cumark to complete the project transformation.

Customer benefits：The large-scale mining inverter after the transformation not only perfectly solves the original problems of the production site, but also ensures the smooth operation of the equipment in the on-site environment to achieve the best working conditions, and at the same time meets the customers to achieve more reasonable configuration applications without increasing the configuration cost, and improves the overall production efficiency. After testing, this working face from the official start of production, the average daily coal mining capacity is about 10,000 tons, the monthly coal mining capacity is about 250,000-300,000 tons, and the monthly advance of 150 meters can successfully complete the set target output every month.

2.Solution

In order to meet the production requirements of the customer's site, the R&D and technical department of Cumark modified the inverter control program according to the system requirements, and adopted the explosion-proof high-pressure frequency conversion intelligent drive system scheme of high-power scraper conveyor.

The project is commissioned and run in the 18106 working face of Xigou Mine, the working face length is 300m, the total length is 3750m, and a BPJV3-3*1600/3.3 mine flameproof and intrinsically safe high-voltage inverter is installed, and a single inverter has 3 independent output circuits. The actual installation of the underground working face requires a frequency converter to be able to drag the main equipment of the two mining surfaces of the scraper conveyor and the transfer machine at the same time, of which the scraper is two 1200KW motors and the transfer machine is a 700KW motor. The use of this working face is: the first and third circuit inverters drive two 1200KW scraper motors respectively to run the main and slave power balance, and the second circuit inverter drives the transfer machine to operate.

-The installation configuration system topology map-

-Scraper running current graph-

Data analysis: This inverter adopts the newly developed torque plate control system, which can better balance the running current; The running current curve of the scraper 1-3# head and tail motor basically overlaps, the maximum starting peak current is 429A, the average running current is 78A, and the equipment runs smoothly to meet the production requirements.

-Converter operating current graph-

Data analysis: This inverter adopts the newly developed torque plate control system, which can better balance the running current; The 2# motor of the transfer machine has a maximum starting peak current of 262A and an average running current of 67A, and the equipment runs smoothly to meet the production requirements.

 

Features and Benefits：The large-scale mine flameproof and intrinsically safe high-voltage independent combination inverter used in the project adopts Cumark's patented technology, and the real high-voltage independent combination inverter is placed in a combination shell between three (two) inverters independent of each other and does not affect each other.

PRODUCT FEATURES

*High reliability and high efficiency based on high-power IGBT

*Based on High Performance Quantity (DTC) control technology

*Low harmonic rectification technology based on 12 pulse waves, output sine wave technology

* The main loop adopts a three-level topology, and the inverter trigger signal adopts optical fiber isolation

* Using water cooling technology, the maximum starting torque and maximum current reach 2.5 times the rated rate

* The distance from the inverter to the motor can reach 3~5km

This series of products saves the deceleration and torsion increase links of large maintenance, high failure rate and large transmission loss for customers, and the comprehensive benefits are greatly improved. Compared with traditional drive products, Cumark mining high-power explosion-proof frequency conversion has the following five innovative technical advantages.

PRODUCT ADVANTAGES

（1）More energy-efficient

Cumark Mine Flameproof and Intrinsically Safe High Voltage Inverter (hereinafter referred to as frequency converter) has a proprietary "energy-saving operation" mode, which perfectly solves the problem of equipment energy consumption through improved control strategies and other technical means, and has superior energy-saving effects.

（2）Smoother
The inverter adopts the newly developed torque plate control system, which can better balance the running current, achieve the dynamic power balance of the main and slave machines independently between multiple machine circuits, and the equipment runs smoothly to meet the modernization requirements of coal mine production.

（3）Safer

In large coal mines, the working face mining height is very high, the load is very heavy, and the scraper transport machine has a heavy load start-up situation, which is easy to jam and break the chain. During normal operation, the maximum output torque and output current are set through the inverter display to ensure that the scraper conveyor can operate safely under heavy load start.

（4）More efficient

The inverter has high automation and reliability, and the production equipment has high operating accuracy, which realizes the efficient driving of key production equipment in special environments such as high dust, high temperature, high humidity, water spray, strong vibration, small space, complex electromagnetic interference and explosive gases in coal mines, and ensures safe and efficient production in coal mines.

（5）More cost reduction

The inverter one-to-three application scheme can realize heavy-duty soft start and soft stop, reduce the impact on the scraper conveyor, avoid conveyor damage and failure to the greatest extent, and at the same time meet customers to achieve more reasonable configuration applications without increasing the configuration cost, and achieve the goal of reducing costs and increasing efficiency, which is a more perfect solution.

3.Project Summary

The "Cumark ×Shanxi Xiegou Coal Mine" project has effectively realized the improvement of the regulation and control performance and energy-saving operation of large-scale mining equipment, actively promoted the technological transformation driven by large-scale mining equipment, strongly supported the construction of intelligent green mines, and provided important technical support for the national implementation of the "dual carbon" strategy and the goal of energy conservation and emission reduction.

After years of technology precipitation and market accumulation, at present, the frequency converter controlled by Cumark has covered the main production links of major mines in China, with stable product performance, safety and reliability, and has reached effective cooperation with many typical coal mining enterprises.

-Some enterprise qualification honors-

 

-Typical Coal Mine Partner-