Optical Fiber Sensor-Based Techniques for On-Line Detection and Location of Partial Discharges in Transformers

ECS-9810688 Wang电力变压器是电力传输中最昂贵的部件之一，其灾难性故障经常在没有警告的情况下发生，导致严重的漏油、火灾、邻近设备的广泛损坏以及服务的重大中断。 单个Transformer故障的成本可能高达数千万美元。 特别是超高压电力变压器具有超过3%的不可接受的年故障率，这主要是由于通常由局部放电引发的介质击穿。 因此，必须及时检测和定位重要变压器的局部放电，以在灾难性故障之前提供警告，并防止大规模的损害成本。 然而，由于局部放电在线检测和定位技术存在巨大的技术困难，目前还没有准确可靠的技术来满足电力工业的需要，在这个为期三年的项目中，弗吉尼亚理工大学电气工程系的主要研究人员提出开发用于电力变压器局部放电实时在线检测和定位的光纤技术。 该计划将包括两个阶段，包括开发高灵敏度，小型化的光纤声传感器，以及使用开发的传感器仪器进行局部放电检测和定位的实验室和现场调查。 其基本原理是利用几个新开发的小型化光纤传感器放置在变压器内的不同位置，以检测局部放电产生的声发射。 基于声到达时间差和几何三角测量，可以确定局部放电的位置。 除了位置之外，声信号幅度、频率和时域图案一起也可以产生关于局部放电的附加信息，诸如放电强度类型和阶段。 为实现技术目标，将执行七项任务。 这些任务包括：1）指定技术要求，2）传感器设计和制造，3）系统测试和优化，4）研究Transformer油中的局部放电检测，5）声学信号处理和解释，6）研究变压器中的局部放电定位，以及7）制定技术过渡到工业用途的计划。 该项目的成功完成将导致精确可靠的光纤技术的发展，用于检测和定位局部放电，以满足电力行业对实时在线Transformer健康监测的需求。在该项目中，弗吉尼亚理工大学的研究人员将与美国电力公司（AEP）和弗吉尼亚Transformer公司密切合作。（VTI）。 工业界对该计划的大力参与也将加速已开发的光纤技术向实际应用的过渡。

ECS-9810688WangCatastrophic failure of power transformers, one of the most expensive component in power transmission, often occurs without warning, resulting in serious oil spills, fires, extensive damage to adjacent equipment, and major disruption of service. The cost of a single transformer failure could run into tens of millions of dollars. Especially EHV power transformers have an unacceptable annual failure rate of more than 3% mainly due to dielectric breakdown often initiated by partial discharges. It is therefore imperative that the partial discharge of important transformers be detected and located in a timely fashion to provide a warning before catastrophic failures, and to prevent extensive damage cost. Unfortunately, due to the tremendous technical difficulties encountered by on-line partial discharge detection and location, no accurate and reliable techniques are available to meet the power industry's need.In this three-year program, the principal investigators in the Department of Electrical Engineering at Virginia Tech propose to develop fiber optic techniques for real-time, on-line detection and location of partial discharges in power transformers. The program will involve two stages, including the development of highly-sensitive, miniaturized fiber acoustic sensors, and laboratory and field investigation of partial discharge detection and location using the developed sensor instrumentation. The basic principle is to utilize several of the newly developed miniaturized fiber sensors placed at different locations inside a transformers to detect partial discharge-generated acoustic emissions. Based on the differential acoustic arrival times and geometrical triangulation, the location of the partial discharge could be determined. In addition to location, the acoustic signal amplitudes, frequencies and time-domain patterns together may also yield additional information concerning the partial discharge, such as discharge intensity type and stage. Seven tasks will be performed to achieve the technical goal. These tasks include 1) specify technical requirements, 2) sensor design and fabrication, 3) system testing and optimization, 4) study of partial discharge detection in transformer oils, 5) acoustic signal processing and interpretation, 6) study of partial discharge location in transformers, and 7) develop a plan for technology transition into industrial uses. The successful completion of the proposed program will lead to the development of accurate and reliable fiber optic techniques for detection and location of partial discharges to fulfill the power industry's needs for real-time on-line transformer health monitoring,In this program, Virginia Tech researchers will work closely with American Electric Power (AEP) and Virginia Transformer Inc. (VTI). The strong industrial involvement in the program would also accelerate the transition of the developed fiber optic technologies into practical uses.