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高压断路器是电力系统关键设备之一,对其进行快速故障诊断对于事故发生后快速寻找故障发生的原因,解决事故源,确保电力系统迅速恢复正常运行有重要的意义。通过改进广义径向基人工神经网络(RBF)算法,使其具有快速故障诊断和网络自更新能力,并应用于断路器在线故障诊断专家系统。专家系统通过神经网络处理在线监测装置传送的故障数据,得到故障类型编码,利用该编码通过正向推理从知识库中找出对应的故障类型,并给出合理的故障解决办法。同时,利用神经网络的自更新能力和与专家系统的配合,专家系统还具有新知识的获取能力。 相似文献
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拒动是断路器最严重的故障类型之一,可能导致大面积停电事故,而近年来由于分合闸线圈故障导致拒动时有发生,诊断分合闸线圈的运行状态对于保障电网安全具有重要意义。文中以某型号SF6瓷柱式高压交流断路器中的分合闸线圈为研究对象,通过实验模拟电源电压跌落、供电回路接触不良、铁心卡涩、铁心空行程大这几种典型的故障类型,获取正常与故障条件下的分合闸线圈电流波形。进而采用支持向量机(SVM)算法对分合闸线圈故障进行诊断,特别是采用主成分分析法提取电流波形的特征参数作为诊断依据,实现了对故障的有效识别。基于SVM主成分分析的方法可方便构建故障诊断专家系统,以保障分合闸线圈可靠运行。 相似文献
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非热力学平衡态等离子体技术既是现代工业的关键技术之一,也是未来高科技的重要发展方向。通过仿真研究深入揭示此类等离子体的微观机理,阐明等离子体的宏观特性变化规律,对于提高科学认知水平并促进产业发展具有重要意义。传统的仿真研究主要集中于低气压条件下的非热力学平衡态等离子体,在大气压及更高气压条件下开展较少。本文主要针对高气压非热力学平衡态等离子体,对国内外仿真模型进行了综述。非热力学平衡态等离子体一般包括局部化学平衡和非化学平衡两种状态,前者中的粒子组分可由宏观的热力学统计原理计算得到,后者必需考察微观的物理和化学过程。针对局部化学平衡态等离子体,介绍了双温度条件下微观粒子组分和宏观物理特性分布规律的计算模型,重点讨论了基于质量作用定律、吉布斯自由焓最小化原理与化学动力学方法的粒子组分计算方法;针对非化学平衡态等离子体,介绍了基于漂移-扩散原理的流体模型和化学动力学模型,提出了全局模型与流体模型的联合仿真新方法。 相似文献
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Cold atmospheric-pressure plasma is a new technology,widely used in many fields of biomedicine,especially in cancer treatment.Cold plasma can selectively kill a variety of tumor cells,and its biological safety in clinical trials is also very important.In many cases,the patient's immune level is relatively low,so we first studied the safety assessment of plasma treatment in an immunocompromised animal model.In this study,we examined the safety of immuno-deficient nude mice by oral lavage treatment of plasma-activated water,and studied the growth status,main organs and blood biochemical indexes.Acute toxicity test results showed that the maximum dose of plasma treatment for 15 rain had no lethal effect and other acute toxicity.There were no significant changes in body weight and survival status of mice after 2 rain and 4 min of plasma-activated water (PAW) treatment for 2 weeks.After treatment,the major organs,including heart,liver,spleen,lung and kidney,were not significandy changed in organ coefficient and tissue structure.Blood biochemical markers showed that blood neutrophils and mononuclear cells were slightly increased,and the others remained unchanged.Liver function,renal function,electrolytes,glucose metabolism and lipid metabolism were not affected by different doses of PAW treatment.The above results indicate that PAW treatment can be used to treat immuno-deficient nude mice without significant safety problems. 相似文献
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In this paper, an experimental study on SO2 removal by nanosecond rising edge pulse dielectric barrier discharge (DBD) plasma, generated by multi-needle-to-plane electrodes, is carried out. The mechanism of the effect of various factors, such as gap size between dielectric barrier and discharge needles, environmental humidity, and inlet speed of gas flow upon the removal efficiency of air purification is analyzed. The studies show that SOs removal efficiency improves with the increase in the gap size between dielectric barrier and discharge needles in the case of a fixed space between two electrodes, and also improves with the increase in the environmental humidity. For a mixed gas with a fixed concentration, there is an optimal inlet speed of gas flow, which leads to the best removal efficiency. 相似文献
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高压断路器分合闸线圈在长期运行条件下,会受到温度、湿度、盐雾等环境因素的影响,其性能也会发生相应的劣化.采用湿热试验考察温度、湿度对252 kV断路器分合闸线圈的影响,采用交变盐雾试验考察温湿度及盐雾对252 kV断路器分合闸线圈的综合影响,研究了分合闸线圈在相应试验条件下的劣化情况以及分合闸线圈电流的变化情况.研究结果表明,在湿热环境下,252 kV断路器的分合闸线圈性能的劣化是一个突变过程,无法通过分合闸线圈电流进行反映;在盐雾环境下,252 kV断路器的分合闸线圈性能的劣化是一个非线性的加速过程. 相似文献