For the difference of thyristor junction temperature at all levels in the transducer valve assembly in the series water circuit, an equivalent model of thyristor junction temperature calculation for the valve assembly is established, and PLECS simulation software is used to simulate and solve the junction temperature at all levels of the thyristor and check the junction temperature of the thyristor from the highest temperature of the measured radiator surface, and the results of the junction temperature checking show that the equivalent model of thyristor junction temperature calculation for the valve assembly has a high accuracy.

高压直流换流站内滤波电容器的噪声问题十分严重,是换流站内的主要噪声源.过量的振动和噪声会影响换流站内电容器的寿命以及周围的环境,亟需掌握其声振规律,为电容器的本体和辅助降噪措施提供理论支撑.针对滤波电容器可听噪声机理和特性不明确的问题,分析了滤波电容器的内部受力和振动机理,并在符合国家标准的半消声室内研究了不同激励下滤波电容器的辐射噪声特性.测试结果验证了所提电容器噪声的产生机理.该研究对滤波电容器减振降噪措施的提出具有重要的理论指导意义.

红外热成像因其具有非接触性、灵敏性等优点,已被广泛应用于电力设备的带电检测及其诊断中.其中,对设备快速精确地识别定位是电力设备智能诊断的关键.然而利用传统机器算法对电力设备图像进行识别定位,存在泛化能力不强、鲁棒性较差等不足.针对此问题,开展基于R-FCN区域全卷积网络的绝缘子红外图像识别研究.在TensorFlow框架下搭建R-FCN检测模型,并利用迁移学习方法初始化模型权重,以提高训练效果.最后,将所研究算法与Faster-RCNN和SSD模型进行对比.实验表明,R-FCN模型的检测精度为89.2%,检测速度为23 fps,具有较高的精度和速度.该算法为绝缘子的智能诊断奠定坚实基础.

With the improvement of people's living standards and the increasingly strict environmental protection regulations, the noise problem of filter capacitor has attracted more and more attention, and has become the primary problem of noise reduction in converter station. Aiming at the problem of unclear noise mechanism of filter capacitor, based on the principle of electric field force on the electrode plate, this paper analyzes the influence of the residual charge on its force and the probabilistic statistical characteristics of the random distribution of force caused by the uncertainty of residual charge, which provides a reference for the study of vibration and noise mechanism of filter capacitor.

对接地网进行准确的腐蚀诊断是电力工程中十分关注的问题.为了解决接地网腐蚀诊断过程中计算方程组欠定所导致的诊断精度不高,效果不理想的问题,文中提出一种基于支路电压扰动的接地网腐蚀诊断方法,该方法通过接地网腐蚀前后支路电压的扰动实现腐蚀缺陷支路的定位和腐蚀程度的判断.文中首先理论分析接地网支路电压对支路电阻的灵敏度;其次,利用支路电压扰动特性,建立接地网腐蚀诊断模型,得出支路电压扰动峰值位置、大小与接地网腐蚀支路位置和腐蚀程度的映射规律;最后,实验验证了该方法能够对接地网的支路腐蚀进行有效的诊断.

Infrared thermal imaging technology plays an important role in evaluating the operating condition of electrical equipment. This article focuses on two critical environmental factors, namely, wind speed and ambient temperature. They interfere with infrared detection and fault diagnosis by affecting the actual temperature of the fault area. In this article, we use the principle of heat transfer to explore the affected conditions and the changing laws of diagnostic indicators. We provide a solution for diagnosing the live equipment fault area after compensating for the infrared temperature. Both the simulation and experimental results show that the method can obtain the temperature of the equipment fault area under different environmental conditions for different electrical equipment failures when they meet the temperature compensation conditions. The method can eliminate the influences of wind speed and ambient temperature on the results of infrared temperature measurement and achieve a unified solution to the problem of multiple types of electrical equipment. This breaks through the barriers of infrared temperature measurement applications limited by the on-site environmental conditions. The proposed method can serve to further improve the existing evaluation standards. The results of the article are useful for troubleshooting equipment and improving the accuracy of the infrared diagnosis of live equipment.

基于电网络理论分析方法,设计开发了一套基于循环电压测量法的接地网故障定位装置,实现了接地网的小电流注入、节点毫欧级别低电位和支路毫欧级别的低阻抗的自动循环精确测量;同时利用多态近似解方法求解支路阻抗变化,实现故障精确诊断及定位.通过开展系统的实验室和现场试验测试,装置的可行性及准确性得到了验证.

The present "condition-based maintenance decision making" of power transformers will cause large financial losses to electric enterprises, because of not having taken reliability and economy into consideration. To solve this problem, a maintenance decision-making model with the consideration of reliability and economy was established to choose the best maintenance strategy for oil-filled transformers. With the corrected parameters of operating environment and maintenance records, a condition assessment model including DGA test, oil test, and the electrical test was proposed to decide the comprehensive health index of transformers. After establishing the relationship between the fault rate and the comprehensive health index, a reliability evaluation model was formed, which can simulate the impact of different maintenance types. Taking the reliability and economy operation of transformers into consideration, a particle swarm optimization method was developed to solve the optimization model and select the best maintenance strategy according to the current condition of transformers. Two cases were studied and the results demonstrate that the proposed model offers an improved maintenance strategy.

The location and topology of grounding grid conductors are necessary to corrosion diagnosis and digging in most cases. In this paper, an integrated detecting device for grounding conductor buried position is designed. Based on the principle of magnetic field method, a multi-layer cascade PCB hollow coil sensor is designed. AC excitation current source, 16-channel control circuit, lock-in amplifier (LIA) circuit and 4-channel synchronous acquisition circuit are realized. The experimental test is completed for the integrated detection device, and results verify the feasibility of the system.

对某换流站6支直流穿墙套管的“异常”红外热像特征进行了长期跟踪检测,对其红外特征随季节变化的一些规律进行分析与总结,认为该6支套管的“异常”红外热像特征主要是与随季节性变化的周围环境(空气流动、雨水冲刷)、表面污秽分布情况具有一定的关系.通过红外图谱的正确分析,可较准确地判断穿墙套管的运行状态,同时提出了一些对穿墙套管运行维护管理的建议.

±800 kV天山—中州(简称天中)特高压直流输电工程投运后,直流系统一旦出现单极大地或不对称运行方式,很大的入地电流就会对河南电网产生不利影响。为此,结合河南电网实际运行情况,建立了河南电网直流偏磁分析模型,分析了主变直流偏磁分布特性,并结合现场实测,制定了河南电网直流偏磁分级防护治理方案,研制了带可靠返回系统的电容型直流抑制装置并挂网运行。研究结果表明:直流偏磁电流的大小主要受地表电位分布的影响,同时还受变电站间距离及出线数量的影响,需特别关注站间距离远、出线数量少的变电站直流偏磁问题;应对直流偏磁超标的变电站进行治理,同时对受直流偏磁影响显著的变电站加强直流偏磁监测;所研制的带可靠返回系统的电容型直流抑制装置,实现了控制系统断电时旁路保护的可靠动作,有效地治理了220 kV明河变电站直流偏磁超标的问题,确保了河南电网的安全可靠运行。这些研究结果有效地解决了天中特高压直流输电工程投运对河南电网主变直流偏磁的影响。

谐振是一种稳定的状态,谐振过电压由于持续时间长危害性大,一旦发生,往往会造成电气设备的损坏和大面积的停电事故,因此需要重点关注及防范。文中介绍了一起因线路高抗与线路容抗因参数谐振造成的同塔双回输电线路电压异常事件。通过电压及电流仿真计算与故障波形的对比,分析了事件发生的原因。同时,为避免今后类似故障提出了建议。

With the continuous expansion of the grid, 220 kV voltage grade power transmission networks are involved in the life of people more and more. How to evaluate the environmental influencing factors of the 220 kV electric power transmission and distribution project objectively is a more and more practical serious problem. In this paper, taking 220 kV proposed electric power transmission and distribution project as an example, the author introduces the evaluation factors, especially the current monitoring, analogy monitoring and model predictive, in-depth analysis of the whole process of the environmental impact assessment, it also gives some positive references to instruct such work as the environmental impact assessment of the electric power transmission and distribution project.

运行电压下的全电流及阻性电流测试是日常判断金属氧化物避雷器(MOA)性能状态的重要方法,不同于一般的500 kV变电站,特高压变电站MOA由于诸多被放大的因素影响,有时带电检测数据按照规程不能轻易判断MOA当前的状态.对特高压变电站金属氧化物避雷器(MOA)两年的带电检测数据进行分析,对其中的规律进行总结,并提出若干建议,对特高压MOA的运行及维护具有一定的指导意义.

电动自行车的使用已经非常普及，其安全性也一直备受争议，在充电状态下引起火灾的案例很多，其源头往往集中在蓄电池和充电器两个部位。本文通过理论分析、实地调研及模拟试验对电动自行车充电器长时间空载状态下是否会引起严重发热起火进行了分析，对国内电动自行车充电器的安全使用具有一定的借鉴意义。

A new composite grounding body material based on modified graphite is developed according to the shortcoming of traditional grounding body materials which are prone to corrosion and the delvlopment requirement of global energy internet. The conductivity, dense structure, mechanical properties, tensile strength, compressive strength and folding quality of the grounding body is improved by modified graphite material and servo stainless alloy body inside. Test results and practical engineering application show that the modified graphite composite grounding body is suitable for substations and transmission line tower grounding grid.

以河南省某220 k V电磁环网开环点断路器雷击典型事件分析为例,获得雷电波侵入到断开的断路器发生全反射是引起河南省近年来多次开环点断路器损坏事件的主要原因,并提出在易遭受雷击的开环点线路入口装设MOA是预防断路器损害事件发生最安全经济有效的办法。