At 9 a.m. onJune 14, 2023, the lecture "High-power Electric Drive System - MineApplication Status and Development" organized by Heng Ai Jing Cheng Teamwas held in the second academic lecture hall of the School of Management,attended by 110 graduate students from the School of Electrical Engineering,and presided over by Professor Zhang Xing.
Fig1. Auditorium in the Second Academic Lecture Hall
The speaker of this lecture is ProfessorTan Guojun, who introduced the application status and future developmentdirection of high-power electric drive systems in the mining industry. Heexplained the fundamental concepts of high-power electric drives and how theycan be applied to meet the specific requirements of mining operations.
Fig2. Professor Tan Guojun gives a lecture
Firstly, thehost, Professor Zhang Xing, warmly welcomed Professor Tan Guojun and expressedgratitude for his presence. He proceeded to introduce Professor Tan Guojun'sprofessional background and research accomplishments. Professor Tan Guojun hasdedicated himself to scientific research and promoting technology in the fieldof high-power transmission with full digital control. With extensive experiencein experimentation, he possesses unique technical insights into the applicationof high-power electric transmission control systems for mining operations.Subsequently, Professor Tan Guojun began a wonderful presentation. He hasdivided his report into six chapters covering the current situation,challenges, characteristics, applications, and future development directions ofelectric transmission in mines. The comprehensive report that he presentedoffered the audience numerous new ideas and insights. Finally, Professor ZhangXing summarized the contents of Professor Tan Guojun's report and expressedgratitude for his visit. He warmly welcomed Professor Tan once again.
Fig 3. Professor Zhang Xing presided over the lecture
Professor TanGuojun first introduced the current situation and challenges of mine electrictransmission. He pointed out that electric transmission equipment runs throughthe production links such as coal mining, lifting and transportation, as wellas the safety and security links such as ventilation and drainage, and is thecore equipment of coal mine production. At present, the electric drive systemconsumes more than 85% of the mine's electrical energy, so the electric drivesystem determines the mine's energy consumption level, safety level andproduction efficiency. Professor Tan Guojun then introduced the characteristicsof mine electric transmission, which is mainly divided into five categorys,namely, large power range, underground equipment limited by space, humidity andexplosion-proof conditions, load diversity of working conditions, large changesin load state, difficult maintenance, high equipment reliability requirements,and the organic combination of intelligent mine construction and transmissionsystem. Professor Tan Guojun took the comprehensive mining unit, coal miningmachine and belt conveyor as an example to introduce the applicationcharacteristics and technical difficulties of the mine transmission controlsystem, such as high voltage level, large installed capacity, large startingtorque and deep magnetic weakening. Professor Tan Guojun combined his profoundscientific and practical experience to popularize the electric transmission ofmines for everyone, which is concise and rich in content.
Then, ProfessorTan Guojun introduced mine hoist control. Mine hoists are typicalrepresentatives of mine electric transmission equipment. It has a large powerrange, from a few hundred kW to more than a dozen MW, requiring four-quadrantoperation, smooth speed regulation and high speed regulation accuracy. Hoistsare usually required to transport materials, personnel, bulky and explosives,with a weight range of a dozen to tens of tons, and also require accurateacceleration, deceleration and precise stopping. Professor Tan Guojun pointedout that the control of domestic hoists has gone through four generations ofiterations, from the earliest relay-controlled DC F-D drive and AC TKD drive, toPLC-controlled DC SCR-D drive and AC TKD drive, and then developed to digitaldepth control DC SCR-D drive and AC frequency conversion drive, and finallyupdated to the current all-digital, networked AC frequency conversion drive.
Professor TanGuojun then introduced the explosion-proof frequency conversion technology ofelectric transmission in special environments. Explosion-proof inverter has theadvantages of dustproof, moisture-proof and explosion-proof, and it is mainlyused in coal mines, oil and gas, petrochemical and chemical industries. In themining industry, explosion-proof frequency converters are commonly used inelectromechanical equipment such as scrapers, belt conveyors, transloaders andhoists. Professor Tan Guojun first introduced the four explosion-proof inverterrequirements of the national standard, and pointed out that in industrialapplications, we should pay attention to the actual technical standards. Theoutstanding problems of explosion-proof inverters are mainly reflected in flameproofand intrinsically safe closed cavity, power device heating and heatdissipation, reliable identification of motor parameters, electromagneticcompatibility problems and harmonic problems. Professor Tan Guojun talked aboutthe application status of explosion-proof inverter and introduced in detail theexplosion-proof technology, low switching frequency control, speedless vectorcontrol and EMI suppression technology of three-level explosion-proof inverter.
Professor TanGuojun also explained the network control and fault diagnosis of mine powertransmission. The network control of mine power transmission is based on thefull digital control of the power transmission system, with industrial Ethernetas the link, combined with data fusion and control information fault tolerancetechnology, to realize the information integration and control system of themain power transmission equipment of mine hoist, belt conveyor, fan and waterpump, and finally realize the leap from monitoring to control of large-scaleelectric transmission equipment in mines. Mine power transmission faultdiagnosis is a method based on CSCW technology and multi-agent remote faultdiagnosis. Through the establishment of diagnostic knowledge base and inferencemachine, the communication and collaborative diagnosis and reasoning betweenagents are realized, the network mine hoist fault diagnosis system andoperation status network are released, and finally the fault warning and faultonline diagnosis functions are provided, which greatly improves the safety ofthe mine power transmission system.
Finally,Professor Tan Guojun introduced the development trend of mine electrictransmission. In the future, high-power, increasing voltage levels, and dual PMAC-DC-AC variable frequency drives will become the mainstream ofhigh-performance speed regulation systems. The future mine will be a complexsystem with distributed multi-motor drive, and how to better applycommunication technology to the future mine electric drive system has become anincreasingly important research field. Network channel is not only the mediumof general power electronic information transmission, but also can become animportant participant in the mine electric drive system, therefore, in thefuture, the network dispatch should be used to reasonably distribute themovement of power electronic information data flow and improve the performanceof mine electric drive.
DuringProfessor Tan Guojun's insightful speech, we gained a comprehensiveunderstanding of the current state and future trends of high-power electricdrive systems in mining applications. His extensive experience and expertiseprovide us with valuable inspiration and guidance. Professor Tan's vivid andin-depth explanation was very beneficial to us. The Heng Ai Jing Cheng Teamwill continue to organize similar lectures and activities to promote thedissemination and exchange of professional knowledge within the industry.
Fig 4. Second Academic Lecture Hall
Editor: Qian Feng | Photographer: Xu Qian