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1.
由于无损伤检测、便于现场操作等方面的优点,振荡波电压法在电缆局放检测领域受到行业内越来越多的关注。本文首先介绍了振荡波电压法检测电缆局放的基本电路原理,指出应合理选择电感参数以获得合适的振荡频率。通过总结分析国内外一些振荡波电压检测电缆局放的成功案例,得出:开展振荡波电压法测试,需要详细记录测试电缆的各种信息以及测试过程中可能用来评估电缆绝缘水平的多个特征量;可以采取阶梯式的加压方式对测试电缆施加振荡波,每次加压增幅可取0.1~0.5U0。特别对于交接试验,测试结束前需要将振荡电压调至运行电压U0下,以确认经过试验电缆绝缘未受到影响;对电缆绝缘状态的评估需要结合多个电气特征量、各种环境工况以及运行经验进行综合判断。  相似文献   

2.
为提高高压XLPE电缆的局放检测准确性,对局放进行精确定位,本文介绍了振荡波技术进行XLPE电缆局放检测的原理,分析了该技术基于TDR时域反射的局放判断方法,论述了振荡波电压下与工频运行电压下XLPE电缆局放的良好等效性。重点介绍了北京市电力公司最新引进的适用于高压XLPE电缆的OWTS设备的系统结构功能及使用,通过对北京市高压电缆现场振荡波局放测试数据的分析,验证了振荡波技术能够有效的发现并定位对110kV、220kVXLPE电缆的不同类型缺陷局放,并指出振荡波技术针对近端电缆终端局放判断受环境干扰影响过大的问题。  相似文献   

3.
本文作为本刊同题论文系列的第二篇,主要针对在电缆接头上检测发生在电缆接头或发生在电缆本体上局放的局放测试技术,包括局放传感器类型选用,安装位置及安装形态,各种检测方法的灵敏度比较等,通过在电缆线路模型上所进行的模拟实验结果,促使测试人员较准确地理解和掌握有关电缆接头的局放测试原理和检测方法,为电缆线路现场局放实测打好基础。本论文的前一篇主要介绍电缆线路模型的构成和用途;本论文着重介绍在电缆接头上的各种局放测试方法和模拟实验结果;本论文的后续一篇将会着重介绍在电缆终端上的各种局放测试方法和模拟实验结果。  相似文献   

4.
本论文主要是对一套适用于10kV电缆线路的局放测试设备与方法的研究与探讨,着重介绍作者们如何通过试验室的人工模拟电缆局放试验、对不同位置所检测局放信号进行分析比较、进而总结出一套电缆局放设备与测试方法。通过对现场实际运行电缆的局放检测信号进行测试试验的研究及探讨,固化出一套可以推广的电缆线路局放检测设备与方法。  相似文献   

5.
电力电缆线路的带电局放检测已成为一种预防发生突发性故障和保供电的有效手段。由于运行线路上局放的存在和发生机率低,使得现场测试人员很难积累如何识别局放和定位局放的有效经验,局放检测技术始终难以掌握和普及。电力电缆线路局放测试及定位操练模型的研制目的就是要提供一个安全可靠,可触可视和可以根据需要而任意改形的微缩操练平台。作者认为,通过对在模型上的人工模拟局放的检测操练并结合局放自动检测定位程序帮助,可以促使测试人员深刻和准确地掌握有关电缆局放信号的行波特性,传感原理和检测识别方法;对电缆中间接头和电缆终端的局放测试方法、直接注入校正法与间接注入校正法比较、根据反射波时间和对向波时间差的定位原理均可进行模拟试验及验证,为电缆线路现场局放实测打好基础。  相似文献   

6.
模拟局放(PD)信号注入在电力电缆的带电局放测试中越来越扮演重要角色。本文通过介绍模拟PD信 号发生器的基本要求和规格,着重说明PD发生器在电缆带电局放测试中的应用原理及操作方法,并通过一些现场 的实际电缆线路测试案例介绍体现PD注入法对局放信号定性定量的判断和定位测试的有效性,可行性和实用性。  相似文献   

7.
本文介绍了220kV超高压XLPE电缆局放测试技术在北京电力公司的现场应用情况,重点介绍了测试原理、电极安装、选频、校准等现场操作要求及注意事项。  相似文献   

8.
本文为分析电缆GIS终端环氧套管气泡缺陷引起的局部放电数据,并在试验室进行GIS终端环氧套管气泡缺陷的局部放电测试,通过3种检测方法均获取有效的局放检测图谱,为现场检测GIS电缆终端局部放电的诊断提供了缺陷典型图谱。  相似文献   

9.
耐压试验同时进行局放检测的高压试验已逐步成为电缆线路竣工投运前或进行维修维护后验证线路绝缘品质的一种有效手段。本文通过报告一例长距离多接头的大规模220kV电缆线路耐压局放同步检测试验,着重介绍应对大规模电缆线路耐压局放试验的基本步骤和方法,主要通过大量图片来展示如何使用和安装高频脉冲电流局放传感器HFCT以实现高灵敏度和高质量的局放检测,同时也介绍了分布式光纤局放同步检测装置的系统构成及其功能特点。对于如何应对使用非无局放耐压电源所必须承受的强大电晕放电噪音干扰,通过试验过程中的一些数据案例分析,说明了线路各个接头点局放检测的同步性及其可比性可以成为区分电缆内部信号与外部信号的有力判据。论文最后还介绍了对于个别维修后作为重点监护的接头,加装了几套短时性或临时性的局放在线监测装置实施短期连续实时监测,为电缆线路的安全运行和维护管理提供有力的数据支持。  相似文献   

10.
局部放电测试技术对高压电缆尤其是电缆附件的绝缘检查是非常有效的方法[1-3]。本文主要介绍TeckImp高压电缆局放测试系统及其在现场的应用情况。试验结果表明,该系统能够有效地将放电信号从外界噪声干扰中分离出来,并对每一类放电进行识别,从而发现电缆设备的潜在缺陷。  相似文献   

11.
Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P < 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (>0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P <0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P < 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD.  相似文献   

12.
Objective: To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods: SD rats served as both donors and recipients. 4℃ sodium lactate Ringer's was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava (IVC) inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results: Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion: This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment.  相似文献   

13.
目的:评价使用安心颗粒对急诊经皮冠状动脉介入术(PPCI)术后生活质量的影响.方法:将160例接受PPCI的急性ST段抬高型心肌梗死患者随机分为安心颗粒组(术前顿服安心颗粒8.8g,术后安心颗粒4.4 g/次,每日2次)和对照组(仅接受基础药物治疗).所有患者均服用阿司匹林、氯吡格雷和阿托伐他汀.分别在入院时、出院前1d、出院后180 d时,应用心肌梗死多维度量表(MIDAS)、中文版SF-36评价量表对患者生活质量评分.并观察术后30 d以内的出血并发症、血小板减少症发生情况.结果:入院时和出院前1d,两组患者的心肌梗死MIDAS、SF-36量表评分比较无差异(P>0.05);出院后180 d时,与对照组比较,安心颗粒组MIDAS、SF-36评分明显减低(P<0.05);组内与入院时比较,两组出院前1d、出院后180 d时,MIDAS、SF-36评分均降低(P<0.05).两组患者在随访期间均无大量出血、少量出血、重度和极重度血小板减少症发生,安心颗粒组有4例、对照组有7例发生不明显出血(P>0.05).两组发生轻度血小板减少症的患者数比较无差异(P>0.05).结论:PPCI使用安心颗粒,能改善急性ST段抬高型心肌梗死患者的生活质量,且不增加出血风险.  相似文献   

14.
Objective:To investigate the influences of urapidil and nicardipine on rabbit sinus function,atrio-ventricular node function and hemodynamics.Methods:Thirty-two Angora's rabbits were selected and randomly divided into four groups.U1 group:urapidil 0.25 mg/kg;U2 group:urapidil 0.5 mg/kg;N1 group:nicardipine 10 μg/kg;N2 group:nicardipine 20 μg/kg.All these medicine were administrated within 30 seconds.Measurements were taken before and after the administration of urapidil or nicardipine for the following data:mean blood pressure(MAP),heart rate(HR),sino-atrial conduction time(SACT),maximal sinoatrial recovery time(SNRTmax)corrected sinus node recovery time(CSNRT),index of sinus node recovery time(SNRTI),Wenckebach A-V conduction frequency (WB),and P-R interval.Results:Significant MAP and HR changes were identified in all of the four groups before and after administration of both urapidil and nicardipine.No significant changes could be found in the rest of the parameters.Intergroup analysis showed that SACT and CSNRT of N1 and N2 groups were shorter than those of the U2 group(P<0.01);the MAP decreased(P<0.01)and the HR increased drastically(P<0.01).Conclusions:Neither urapidil(0.25 mg/kg,0.5 mg/kg)nor nicardipine(10μg/kg,20μg/kg)has any significant influence on rabbit sinus function or rabbit atrio-ventricular node function.Nicardipine could be a better choice than urapidil for parafunctional sinus node patients.  相似文献   

15.
Objective:To investigate the gene expression of osteoprotegerin(OPG) and osteoclast differentiation factor(ODF) in the bone tissue of patients with hip fracture due to osteoporosis. Methods:OPGmRNA and ODFmRNA in the bone tissue in 50 cases of osteoporosis sufferers(over 50 years old) with hip fracture(Observer Group) and 30 cases of hip facture sufferers with no osteoporosis(Control group) were analyzed with the Semi-Quantitative RT-PCR method. Results:The mRNA expressed of ODF, OPG were both high in the patients with hip fracture. In the control group, the expression of OPG mRNA was observed, while the expression of ODF mRNA was very slight. Conclusion:Aged patients contained all signals including OPG, ODF that are essential for inducing osteoclastogenesis and promoting bone resorption.  相似文献   

16.
Objective:To investigate the clinical features, pathological characteristics and immunophenotype of solid-pseudopapillary tumor of the pancreas(SPTP). Methods:Nine surgically treated cases of SPTP were retrospectively reviewed. Hematoxylin and Eosin(HE) staining and immunohistochemical staining were used to analyze all cases, and the general clinical data was collected. Results:Six patients were asymptomatic except for a palpable mass. Two patients complained of vague-epigastric pain. One patient appeared jaundice. The tumor was encapsulated and solid tissues alternately with cystic tissues. Histologically, the histological structure of solid portion was pseudopapillary with a fibrovascular core. Tumor cells were uniform and medium-sized which were arranged in sheets ets or nests or pseudopapillary patterns. Immunohistochemical studies demonstrated that SPTP proved positive in vimentin(9/9 cases), AAT(9/9 cases), NSE(9/9 cases), ACT(7/9 cases), CK20(2/9 cases), CgA(1/9 cases), S-100(3/gcases), PR(4/gcases), Syn(3/9 cases) and CD56(5/9cases), negative in CEA and ER. Conclusion:SPTP is a tumor predominantly occurring in young women frequently without special symptoms. This tumor has various characteristical histological patterns with different immunophenotype.  相似文献   

17.
In recent years, the author of this essay has applied electro-acupuncture combined with the trigger point needle-embedding for treatment of primary trigeminal neuralgia in 31 cases, yielding satis- factory results as reported in the following.  相似文献   

18.
Objective: To explore the role of matrix metalloproteinase-1,2 (MMP-1, MMP-2) and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) in endometriosis. Methods: The eutopic and ectopic endometria from 40 subjects suffering from endometriosis and regular.endometria from 40 subjects (excluding endometriosis) were collected and examined by in situ hybridization technology and western blot assay. Results: Both expressions of MMP-1 and -2 were stronger in ectopic endometrium and eutopic endometrium than in normal endometrium. On the contrary, the expression of TIMP-1 in ectopic endometrium and eutopic endometrium was lower. The differences were significant (P 〈 0.01 ). Moreover, there was no relationship among the expressions of MMP-1, 2 and TIMP-1 in ectopic endometrium. Conclusion: The expressions of MMP-1, 2 and TIMP-1 lose balance and lack of periodic changes in ectopic endometrium , which explains the biological invasive behavior of endometriosis. It was suggested-that regulating the balance between the MMPs and TIMP-1 should be an ideal therapeutic target to endometriosis.  相似文献   

19.
Prof. SHI Da-zhuo, Ph.D., male, was born on March 20, 1960. Prof. SHI entered the Ph.D. program in 1990 at the China Academy of Chinese Medical Sciences under the supervision of Prof. CHEN Ke-ji, majoring in the treatment of cardiovascular diseases. After receiving his Ph.D. degree in 1993, Prof. SHI started working at the Cardiovascular Center in Xiyuan Hospital affiliated to China Academy of Chinese Medical sciences.  相似文献   

20.
《中国结合医学杂志》2008,14(2):159-159
The 6th National General Congress of Chinese Association of Integrative Medicine (CALM) was convened at 19-20, April 2008 in Beijing. Academician CHEN Zhu, the minister of Ministry of Health indicated at the congress that the integration of Chinese and Western medicine is very well in keeping with the situation of our country and the general rule of development in medical science; and as a good integration of Chinese medicine and Western medicine, it is mutually beneficial and advantageous to both of them. Seeing the creativity shown in integrative medical investigation in theoretic and methodological sides, we should and must persist in and develop it.  相似文献   

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