【作者】 何友忠；

【导师】 熊兰；

【作者基本信息】 重庆大学 ， 电气工程， 2011， 硕士

【摘要】 近年来,随着电力行业的飞速发展,电力系统朝着高电压、大容量的方向发展,保证电力系统的稳定运行越来越重要。一旦发生停电事故,将带来严重的后果。为预防灾难性事故的发生,及时反映电力设备运行状况,对电力设备进行状态监测和故障诊断就显得十分必要。输变电线路搭载的在线监测设备越来越多,覆盖面越来越广,使得设备对野外供电电源的要求越来越高。如何解决户外架空输变电线路在线监测设备的供电问题,成为制约在线监测技术发展的重要因数。本文在前人研制的基于紫外脉冲技术的绝缘子在线监测装置的工作基础上,针对户外架空输变电线路在线监测设备的供电难题,研究了采用电流互感器取能和锂电池协同供电的方法。该方法利用电流互感器从输电线路电磁感应获取能量,经整流滤波处理直接为输电线路在线设备供能。考虑到输电线路电流不稳定,增加了锂电池充放电电路和泄流保护电路,输电线路过低造成的供能不足时采用锂电池做备用电源,泄流保护电路用于输电线路电流过高时的保护后续电路。通过实验室模拟试验,获取了不同输电线路电流状态下取能设备的工作状态,并实地试验验证了取能设备的实用性。主要包括以下几方面的工作:①分析了常见在线监测装置的工作机理,分析了在线监测系统的运行环境、工作状态及功率特性;②分析了从输电线路取能的电流互感器的工作原理及能量传递规律,建立电流互感器的等效电路模型,由此获得电流互感器的输出功率与二次侧负载的关系;③优化互感器的设计,计算了各电磁参数与结构参数。同时,针对电流互感器研制了后续的电源管理与保护电路,使之满足特定在线检测设备的供能需要;④设计电源管理电路,分析电源管理电路供电以及锂电池充放电状态;⑤采用从调度所获得的日负荷工作曲线,通过模拟实验和现场实验,检测电源管理电路的运行情况,以及在电网电流稳定与非稳定状况下供电电路长期负载运行的情况;本论文综合了电磁感应供能和锂电池供能的优点,基本解决了在线监测设备的供电难题。该电路体积小,质量小,易于集成,取能系统且扩展性强,经实验证明,能满足输出电压和功率较宽范围变化的要求,对电气设备的状态监测技术的推广应用有着重要的支撑与保障作用。更多还原

【Abstract】 The stability of the power grid is more and more important with the rapid development of electric power industry. Since power failure often produces serious results, online monitoring of the power devices is necessary. However,a broad distribution of the grid makes it difficult. Therfore, it is vital to obtain power from outer area and supply energy for monitoring devices. Thus, it is an urgent research nowadays.This paper is based on the previous research of insulator online monitoring by ultra-violet light detecting partial discharge. A method which obtains energy with CT and uses lithium batteries as backup is proposed. This method adopts current transformer which obtains energy from transmission line. And through rectification and filtering, the energy can be supplied for online monitoring devices. Considering the instability of line current, charging-discharging circuit and overcurrent protection circuit are also added. When line current is low, lithium batteries work as backup. When line current is too high, overcurrent protection circuit prevents follow-up circuits being damaged. In the simulated experiment, we recorded the performance of this method in different line current. And we checked its application in the field test.The research mainly includes:①The theory of online monitoring devices and the analysis of its operation circumstance and power characteristic.②The theory of CT and the energy transmission from transmission line. Circuit model of the CT is built. So, it comes to the relationship between output power and load resistance of CT.③The design of CT is optimized including some parameters. Control circuit for energy transmission is designed and tested to meet the specific needs of on-line detection equipment.④The theory of the Battery management circuit and the analysis of its operation process of the charging and discharging.⑤Simulation and field test are both completed to analyze the performance of the CT energy supplying method in long-term operation.The advantages of supplying energy from electromagnetic induction and lithium batteries backup are illustrated in this paper. The experiment shows that devices based on this method can provide enough power even if line current varies in a wide range from 0 to 1000A. It proposes a practical solution for supplying energy for monitoring devices and promoting the online monitoring techniques.更多还原