Gaoya dianqi, 2007 介绍了德阳绵竹地区因雷击而造成的7台110 kV主变中性点间隙击穿并使其中5台跳闸的情况。详细分析了保护动作行为,并指出了主变压器跳闸的原因。校验了中性点间隙与避雷器之间的配合,提出了增大间隙并延长间隙过流保护动作时限以躲开线路重合闸的方法,以减少停电时间并避免主变压器不必要的跳闸。
胡晶晶, 曾丽, 饶林
doaj
Gaoya dianqi, 2017 变压器作为电力系统的核心设备,在长期的投运过程中也伴随出现了各种各样的可靠性评价方法。其中可靠性评价分为长期分析和短期状态评估。文中重点介绍总结了常用可靠的方法,对各方法的原理和适用情况进行了描述,再对比列出各方法的优缺点,为以后进行变压器可靠性评价时在方法选择上提供指导意见。对于特高压变压器,目前没有针对的评价方法,因设备结构和运行原理大致相同,故可参考现有方法。
许修乐 +5 more
doaj
Gaoya dianqi, 2011 大型油浸电力变压器是电力系统中最关键的设备之一,其故障诊断技术深受关注。为此,笔者在汇总、整理现有的反映变压器运行状态各种数据的基础上,根据目前电力部门对变压器故障的监测与检修状况,按组成结构建立电力变压器故障的特征参量及故障模式的对应关系。利用模糊数学方法分析了不同电气试验项目的隶属函数,克服了隶属函数的形式及其参数选取的固定性及主观性。对于油中溶解气体,由于其自身的特点和重要性,先用三比值法判断故障原因,再用TD图中故障点到原点的距离来确定故障隶属度。其次,结合各个指标参量的特点 ...
袁蕾 +5 more
doaj
[Outcomes of suture-mediated vascular closure device in the closure of left brachial artery access site after thoracic endovascular aortic repair]. [PDF]
Beijing Da Xue Xue Bao Yi Xue BanLi W, Zhang X, Li W, Zhang T, Zhang X.
europepmc +1 more source
[Follow-up study evaluating morphological changes in alveolar bone in the maxillary anterior region after extraction retraction in adult patients treated with clear aligners on the basis of cone beam computed tomography data]. [PDF]
Hua Xi Kou Qiang Yi Xue Za ZhiHong X +5 more
europepmc +1 more source
[Comparison of effectiveness between two endoscopic lumbar interbody fusion techniques and minimally invasive transforaminal lumbar interbody fusion for single-level lumbar degenerative disease]. [PDF]
Zhongguo Xiu Fu Chong Jian Wai Ke Za ZhiLi Y, Kong W, Li J, Ma C, Ren Y.
europepmc +1 more source
[Short-term effecetiveness of endoscopic lumbar discectomy combined with annular suturing in treatment of lumbar disc herniation]. [PDF]
Zhongguo Xiu Fu Chong Jian Wai Ke Za ZhiZhang S, Yao F, Liao Z, Wang T, Shen M.
europepmc +1 more source
[Advancements in biomechanics and orthodontic strategies for clear aligner therapy]. [PDF]
Hua Xi Kou Qiang Yi Xue Za ZhiLei X, Jin F.
europepmc +1 more source
[Early effectiveness and safety of mini open endoscopy assisted anterior cervical discectomy and fusion in treatment of cervical spondylotic myelopathy]. [PDF]
Zhongguo Xiu Fu Chong Jian Wai Ke Za ZhiPan X, Wang X, Wang C, Su W, Sheng J.
europepmc +1 more source
Gaoya dianqi以电力系统中广泛使用的典型三绕组240 MVA/220 kV电力变压器为例，阐述了高阻抗变压器实现的工作原理和4种典型结构特点，分析了不同短路工况下的抗短路能力，并对3种典型结构高阻抗变压器的抗短路性能进行了对比分析，评估了不同结构高阻抗变压器的短路性能优劣性。结果表明，高压内置和串抗结构高阻抗变压器均具有较好的抗短路性能，且串抗结构在高中低绕组轴向力及垫块压缩应力、调压绕组环向应力和变压器端部轴向作用力方面更具有优势，且整体抗短路性能最好。
胡诗尧 +5 more
doaj