高压电压互感器的可靠性数据统计分析

本文根据高压电压互感器现场运行的调查材料,用概率统计的方法求出其寿命函数,并估计其平均故障率,为高压电压互感器的可靠性管理提供依据和参考。     

基于Transformer的强泛化苹果叶片病害识别模型

模型泛化能力是病害识别模型多场景应用的关键,该研究针对不同环境下的苹果叶片病害数据,提出一种可以提取多类型特征的强泛化苹果叶片病害识别模型CaTNet。该模型采用双分支结构,首先设计了一种卷积神经网络分支,负责提取苹果叶片图像的局部特征,其次构建了具有挤压和扩充功能的视觉Transformer分支,该分支能够提取苹果叶片图像的全局特征,最后将两种特征进行融合,使Transformer分支可以学习局部特征,使卷积神经网络分支学习全局特征。与多种卷积神经网络模型和Transformer模型相比,该模型具有更好的泛化能力,仅需学习实验室环境叶片数据,即可在自然环境数据下达到80%的识别精度,相较卷积神经网络EfficientNetV2提升7.21个百分点,相较Transformer网络PVT提升26.63个百分点,能够有效提升对不同环境数据的识别精度,解决了深度学习模型训练成本高,泛化能力弱的问题。     

节能变压器技术动向

变压器高效率化是变配电设备节能的重要课题。本文介绍了高效率变压器的市场、规格化方向、高效率对策、特征及选型原则。     

STUDY OF DIGITAL SIMULATION MODEL FOR THE MAGNETIZING CHARACTERISTIC OF REACTANCE TRANSFORMER

Based on the experiment, magnetizing characteristic and its mathematical model of iron for the reactance transformer DKB has been studied in this paper. Its simulating calculation model has been achieved and implemented by program. The result of the simulation is satisfactory compared with that of the experiment.     

Simulation Propagation of Partial Discharge UHF Signals in Transformer

Many factors affect the propagation of ultra high frequency(UHF) signals caused by partial discharge(PD) on the waveforms and energy of signals in transformer.To investigate the relationshi Pof factors and UHF signals,simulation model of transformer for PD study are established.UHF signals in simulation model of transformer caused by PD are calculated using finite difference time domain method.By means of amplitude and cumulative energy plot of simulation signals,and combing the measured result,the following factors:distance between PD source and detection position,different metallic conductor position around detection position and iron core and winding are researched,which contribute to comprehend the propagation characteristic of UHF signals and detect UHF signals accurately.     

Synthetic Assessment of Power Transformer Condition Based on Matter-element Theory

Condition assessment on power transformer is an important approach to improve reliability of transformer and provide proper decision-making for condition-based maintenance. For long, static assessment method used in the past has already not adapted to the development of modem electricity transmission and distribution technology. So based on the deficiency of fuzzy synthetic assessment method, matter-element synthetic assessment method is introduced. The method can evaluate transformer condition not only in quality but also in quantity. Because each index weight can be given fairly and fast through improved analytic hierarchy process, which need not carry on consistency chec accuracy of assessment can be improved. Examples analysis has proved that assessment method of power transformer condition based on matter-element theory is rational and effective.     

基于框架理论的变电站操作票自动生成系统

介绍了一种基于框架理论的变电站操作票自动生成系统。该系统用框架知识表示法来描述电力系统的设备参数，建构了一个直观的、层次分明的数据结构。通过融合框架理论于面向对象的语言VC 中，开发出了一个集通用、实用、智能于一体的操作票专家系统。     

东深供水改造工程站用电系统的设计

东深供水改造工程站用电系统主要包括莲湖、旗岭、金湖泵站的内部用电路设备的供电系统。泵站用电采用380／220V中性点接地的三相四线制系统供电；为保证机组的安全稳定运行，对机组自用电的叶片调节机构油压装置采用双回路供电。选用站用电系统设备时应满足短路时的动、热稳定，开断电流，开关上、下级的选择性等要求。     

变压器负载试验方法改进研究与分析

工程实际中对于小型试验厂或容量有限的变电站而言,如果在额定电流条件下进行变压器负载试验,需要的电源容量较大,即使利用电容补偿弥补电源容量的不足,所需补偿电容器的体积和质量也会给试验实施带来困难。该文分析了变压器常规负载试验方法及其在工程实际中出现的问题,并有针对性的提出了一种改进的负载试验方法。首先通过计算机仿真验证改进方法的可行性,继而对其进行了现场实践,并对改进方法下的负载试验参数重新进行了计算,同时将改进方法与常规方法进行参数误差分析与成本对比分析。结果表明,该文提出的变压器负载试验改进方法可在不提高电源容量的情况下,大幅减少对中间设备如补偿电容器的限制,从而提高试验操作的效率及试验厂站的经济效益,又可满足工程实际精度要求,因此可以作为常规变压器负载试验的一种延伸和发展。     

有载自动调容配电变压器及其动态降损节能效益分析

为验证有载自动调容配电变压器降损节能效果及其解决“大马拉小车”的机理,根据实测的动态日、月负荷数据,绘制了日、月负荷曲线;对SZ11-M-T型有载自动调容型变压器与S11普通型配电变压器的动态功率损耗进行了综合经济性比较。计算结果表明：对于峰谷用电量差异明显,峰谷负荷轮换频繁的用电区域及用电季节性集中的农村配电区域,避免普通变压器长期处于“大马拉小车”有效途径是使用有载自动调容配电变压器;相对于无载调容,有载自动调容配电变压器降损节能经济效益十分明显,使用范围更广。