School of Electrical Engineering and Automation, Henan Polytechnic University
Henan Key Laboratory of Intelligent Detectionand Control of Coal Mine Equipment
China Coal Research Institute
Shanxi Lanyan Coal-bedMethane Group Co., Ltd.
School of Mechanical Electronic & Information Engineering, China University of Mining and Technology-Beijing

In terms of the collaborative utilization of residual energy and space resources in abandoned mines, under theframework of a green low-carbon multi-energy complementary system, a multi-energy complementary DC microgrid integratingwind-solar-gas-storage for residual CBM drainage in abandoned mine was proposed and constructed with theconsideration of both the electricity demand of coalbed methane (CBM) in the abandoned mine goaf and the power generationpotential of renewable energies in coal mining subsidence areas, as well as the low-concentration gas power generationand energy storage as supplements. Compared with the common DC microgrids, the superposition of multiple unfavorablefactors such as low system inertia, weak grid connection, random changes in distributed power generation andlarge fluctuations in periodically variable working condition load makes the stable operation of the multi-energy complementaryDC microgrid for residual CBM drainage face become a more severe challenges. Therefore, it is necessary to systematicallydiscuss and investigate the key technologies and bottlenecks involved in the multi-energy complementary DCmicrogrid for residual CBM drainage in abandoned mine which is a potential scenario of collaborative utilization of residualenergy and space resources in abandoned mines. First, the topology and components of a multi-energy complementaryDC microgrid for residual CBM drainage were described, and the constraints that need to be considered in the system capacityoptimization were discussed based on an energy flow model. Then, the key technologies including periodically variableworking condition load analysis of CBM pumping motor, coupling of gas-electric conversion link of low-concentrationgas generator, voltage stabilization control and system coordinated operation involved in achieving reliable, stable andcoordinated operation of multi-energy complementary DC microgrid for residual CBM drainage in abandoned mine wereconcluded. The recent research progresses were summarized and reviewed, the difficulties and problems existed in the currentwork were analyzed, and some possible solutions and suggestions for following work were discussed. Furthermore, itis pointed out that it is urgent to address the bottleneck issues behind the key technologies such as the joint modeling methodof both gas-electric coupling long-time scale of the low-concentration gas generator and short-time scale of wind-solarstorage,as well as the bus voltage oscillation mechanism caused by multiple unfavorable factors such as low inertia, weakconnection and large disturbance. Finally, the feasibility and application prospect of constructing a multi-energy complementaryDC microgrid for residual CBM drainage in abandoned mine were prospected from the aspects of existing workbasis, research progress and economic benefits assessment.

河南省自然科学基金资助项目(212300410147)；河南省高校基本科研业务费专项资金资助项目(NSFRF230419)；河南理工大学青年骨干教师计划资助项目(2022XQG−15)

王浩，李斌，王雨婷，等. 废弃矿井残余煤层气开采多能互补直流微电网关键技术及瓶颈问题[J]. 煤炭学报，2023，48(4)：1798−1813

WANG Hao，LI Bin，WANG Yuting，et al. Key technologies and bottlenecks of multi-energy complementary dc microgrid for residual coalbed methane drainage in abandoned mine[J]. Journal of China Coal Society，2023，48(4)：1798−1813