Results 81 to 90 of about 1,797 (167)
Research on Large-Signal Stability Assessment Methods of DC Microgrids Based on Artificial Intelligence [PDF]
ObjectivesDC microgrids are prone to the issue of large-signal stability due to the low inertia and constant power load characteristics. Traditional model-based methods involve complex calculations and are difficult to solve.
HONG Tao +4 more
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Application of a GA-BP Neural Network in Accurately Characterizing the Diffusion Range of Groundwater Pollutants [PDF]
This study addresses the issue of unevenly distributed sampling points, which leads to inaccurate characterization of pollutant diffusion ranges. Using ArcGIS spatial interpolation, the distribution of Mn2+ ions in a chemical park was analyzed, revealing
Jiayun JI +4 more
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Gaoya dianqi, 2018 目前的柔性直流输电系统无法实现直流侧短路故障的清除,导致故障时所有换流站长时间停运。为解决该问题,提高系统可靠性,通过对系统故障电流的产生机理及直流开断原理的研究,以及直流断路器转移回路参数对开断性能影响的仿真分析;提出了一种开断电流500 A的机械式直流断路器及使用该断路器快速清除故障的方法;并搭建低频振荡试验回路验证直流断路器的开断性能。试验结果显示:文中提出的直流断路器稳定开断500 A直流电流,并使用该断路器的故障清除方法能够有效地缩短系统恢复时间,提高了系统稳定性,保证了电能质量。
朱继斌 +4 more
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Research on time–frequency characteristics of electromagnetic signals from coal and rock blasting based on DBO-VMD filtering [PDF]
In shaft mining, conventional vibration monitoring of blasting operations is often affected by environmental factors and system limitations, complicating the extraction of coal–rock rupture signals.
Dazhao SONG +7 more
core +1 more source
Gaoya dianqi, 2018 文中理论推导了交流电网单相短路接地、两相短路和两相短路接地这3种不对称故障类型下,针对不同换流变接线方式（Y-Y型和Y-D型）,故障特征量对直流换相过程的影响。基于向上±800kV直流输电工程PSCAD/EMTD电磁暂态仿真模型,仿真验证不对称故障类型对换流变Y桥和D桥换相失败影响的差异性。此外,还讨论了不对称故障类型对临界过渡电阻的影响规律,得到了不同故障下最易发生换相失败的换流变接线方式和导致换相失败的主要原因,对换相失败有一定的预测作用,并总结了这3种不对称故障类型对换相失败的影响程度。
李江涛 +8 more
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Mine cable partial discharge denoising method based on multivariate variational mode decomposition and improved wavelet threshold [PDF]
The insulation state of the mine cable plays an important role in the stable operation of the mine power supply system. Partial discharge on-line monitoring is an important means of cable insulation state monitoring.
Jiyuan CAO +6 more
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Gaoya dianqi, 2020 干式空芯电抗器匝间短路故障发生概率大,若不及时排除,会造成严重的后果,而常用的传统检测方法存在准确度和灵敏度不足的问题。针对此问题,文中提出了一种基于磁场探测法的电抗器匝间短路故障检测方法,首先通过滑动均值平滑采样数据,再根据误差限阈控制模型判断是否发生匝间故障,实现电抗器匝间短路故障在初期和发展期的在线监控和及时准确的故障预警。工程实例验证表明:文中所提出的方法相较于传统方法,信号强度增强了50～100倍;同时,所提出方法对于是否发生匝间故障具有良好的可靠性和稳定性。综上所述,文中方法可应用于工程实际,
郑宗安
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Dianci bileiqi, 2019 在小电阻接地系统中,若线路发生单相接地故障将在故障点产生较大电流,数百安的接地电流会引起地电位超过安全允许值。对某市10kV小电阻接地系统发生单相接地短路后会造成地点位升高进行了定量分析。首先,对该线路在单相接地短路时故障短路电流进行了模拟理论计算和MATLAB仿真,得到故障发生后将产生超过安全允许的电流值。其次,运用有限元分析软件ANSYS分析了杆塔旁土壤地电位分布,并分析其跨步电压对人身安全的影响。结果表明:故障发生后杆塔附近的跨步电压较大,远远超过人身安全允许值。最后,基于人身安全 ...
毛兴华 +4 more
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