Results 11 to 20 of about 1,591 (104)

Hotspots of zoonotic disease risk from wildlife hunting and trade in the tropics 野生动物狩猎和贸易引发人畜共患病风险的热带热点地区

open access: yesIntegrative Conservation, Volume 2, Issue 4, Page 165-175, December 2023., 2023
There is a lack of knowledge of which species and areas have a high risk of zoonotic disease spillover due to wildlife hunting and trade. We combined maps of hunting pressure, recent data sets on human‐shared pathogens, and trade volumes for 614 mammalian host species to map zoonotic disease risk from wildlife hunting and trade pantropically.
Jacqueline Choo   +4 more
wiley   +1 more source

Successful surgical removal of a pheochromocytoma in a mare via trans‐costal approach

open access: yesEquine Veterinary Journal, Volume 55, Issue 6, Page 1012-1020, November 2023., 2023
Abstract Background Pheochromocytomas have been previously reported in horses, but successful antemortem diagnosis and surgical removal without recurrence of clinical signs have not been described. Objective To report the clinical presentation, diagnostic evaluation, surgical technique, anaesthetic management and post‐operative care of a mare diagnosed
Thomas J. O'Brien   +6 more
wiley   +1 more source

柔性直流并入城市电网后对换流站近区短路电流的影响研究 [PDF]

open access: yes, 2023
大型城市供电电网短路电流已经接近断路器遮断容量,柔性直流接入系统后,会在故障期间提供工作电流,导致交流系统短路电流超标,柔性直流输送功率受限。从柔性直流内外环控制方式及交流系统短路电流计算原理出发,分析得出柔性直流短路电流的幅值和相位对并网点的短路电流影响均较大,其中幅值受外环电流限幅环节的影响易于控制,因此需着重对相位进行控制。基于此提出了一种降低柔性直流输电换流站两端PCC点短路电流的控制策略。以厦门柔性直流工程为例,开发了交直流混合模型,与实测波形对比验证了模型的正确性。通过对不同类型故障下 ...
寇龙泽, 朱琳, 范征, 谷怀广
core   +1 more source

Research on Construction Mode of Large-Scale Offshore Wind Power Centralized Transmission [PDF]

open access: yes, 2023
[Introduction] Offshore wind power has become a research hotspot in the development of global wind power. China's offshore wind power is still in its infancy, the current operation mode is not conducive to the large-scale centralized transmission of ...
Ni LI   +3 more
core   +1 more source

直流故障引发直流外送系统新能源脱网问题研究 [PDF]

open access: yes, 2023
含高比例新能源的直流外送系统由于送端发电设备支撑能力薄弱,在直流故障发生后新能源发电设备面临着过电压脱网风险。为了防止新能源脱网事故的发生,首先建立新能源直流外送系统仿真模型分析新能源机端暂态过电压形成机理,其次根据无功传输规律分析常规机组、调相机、电气距离等因素对新能源脱网的影响,定量分析常规机组的电压调节灵敏度,在此基础上利用新能源短路比指标对新能源脱网情况进行量化分析,最后根据分析结果提出了提高短路容量、提高风机高压穿越能力等预防直流故障后新能源脱网的策略 ...
严欢   +5 more
core   +1 more source

New Generation High-Performance VSC-HVDC Back-to-Back Technology and Application in Project [PDF]

open access: yes, 2023
[Introduction] Due to the dense load, complex grid structure, and close electrical connections in the Guangdong power grid area, there are three major problems for a long time: the risk of large-scale power outages, the interaction between AC and DC, and
Bo ZHU   +5 more
core   +1 more source

适用于直流配电网故障选线的电力电子变压器分步闭锁方案 [PDF]

open access: yes, 2023
级联H桥型电力电子变压器(power electronic transformer with cascaded H-bridge,CHB-PET)是柔性变电站的重要组成设备之一,在直流配电网中具有重要作用。当CHB-PET低压直流侧发生双极短路故障后,故障电流上升速度快且幅值较高,易导致电力电子器件迅速闭锁,使低压直流电网保护难以准确获取故障信息。针对CHB-PET低压侧多分支直流配电网,提出一种基于PET分步闭锁的故障穿越策略。当检测到PET低压侧直流系统故障后 ...
于弘洋   +5 more
core   +1 more source

考虑光伏消纳的配电网储能与直流选址定容协同规划 [PDF]

open access: yes, 2023
大规模分布式光伏的接入将对配电网的安全经济运行带来重要影响,分布式光伏发电的时效性变化和光伏装机的区域性差异为有效进行新能源消纳带来挑战。为此,通过提出配电网储能与直流线路协同规划架构,针对光伏随时间波动的不平衡,使用储能装置进行电能存储,实现电力的削峰填谷。针对区域光伏分布不均,通过建设直流线路以实现区域间能量互济,消纳光伏溢出区域的发电量。进一步,以投资成本、维护成本和电能费用构成的年综合费用最小为目标,构建储能及直流线路选址定容的交直流配电网优化规划问题,实现区域内和区域间光伏溢出功率的高质量 ...
刘俊杉   +5 more
core   +1 more source

海上风电柔性直流系统设计及工程应用 [PDF]

open access: yes, 2023
针对中国第一个海上风电柔性直流送出工程—江苏如东工程,从系统拓扑方案构建、过电压与绝缘配合、系统功率盈余问题与交流故障穿越技术以及控制保护技术等方面开展了深入研究,构建了轻型紧凑化的海上风电柔性直流系统拓扑方案,取消了海上换流站的启动回路与接地回路等;提出了海陆换流站的避雷器配置方案与参考电压的选取原则,形成了海陆换流站的绝缘配合方案的典型范式;提出了集中式、分布式、混合式直流侧有功功率动态平衡装置的典型拓扑方式,解决了陆上换流站交流侧故障穿越难题;提出了工程的整体控制保护方案 ...
卢亚军   +6 more
core   +1 more source

Collaborative Control Method for Offshore Wind Farms with Friendly Access to Hydrogen Energy Systems During Typhoons [PDF]

open access: yes, 2023
[Introduction] With the steady progress of the carbon peaking and carbon neutrality goals, more and more distributed renewable energy is connected to the power grid.
Enyan XIE   +4 more
core   +1 more source

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