【作者】 王维民；

【导师】 王珏；

【作者基本信息】 燕山大学 ， 测试计量技术及仪器， 2000， 硕士

【摘要】 随着工农业经济技术的飞速发展，各行各业对电力系统的可靠性提出了更高的要求。提高供电可靠性由多种方法，其中在运行中对高压设备的在线监测是一种重要的且行之有效的防范措施。本课题是针对电力系统中高压设备（如：高压、超高压变压器，大型电机、高压开关、大型发电机等）的运行状态监控而提出的。同时，温度监测对于高压设备的安全、经济运行和使用寿命有着决定性的作用，因此，为了使这些设备处于最佳运行状态，对其热点温度的测量是十分必要的。 通过查阅近四十年来国际国内关于高压电气设备温度监控方面的文献资料，并深入分析研究之后，针对目前在这一领域内存在的测量精度低和长期工作稳定性差的难题，本课题提出了利用半导体光吸收原理实现对大型电力设备内部温度实时在线监测的方案。设计了系统光学部分结构和电气部分的实现电路。系统中光源波动和光探测器性能不稳定是影响系统精度和长期工作稳定性的主要原因，针对系统中光源波动问题，系统结构中增加了光反馈自适应模块，实现了对光源光功率的稳定；系统中增加了参考光源，并将测量信号和参考信号耦合到同一光纤，由同一探测器转换成电信号，这样由于探测器性能不稳定对测量信号和参考信号的影响程度相同，从而消除了由于探测器性能不稳定对系统精度的影响。本系统中设计了一种新型的信号分离电路，可以分别检出测量信号和参考信号，并滤除环境光和探测器暗电流噪声，提高了系统的信噪比。另外，本系统中还设计了看门狗电路和软件抗干扰措施，进一步增强了系统的稳定性。 实验研究表明，系统精度可达到±1°c，分辨力为0.1°c，响应时间为1ms，基本上达到了绝大多数电力工程应用的要求。更多还原

【Abstract】 Nowadays, with the development of industry and agriculture at high speed, higher and higher requirements of reliability and security for electric power system are put forward. There are many means to improve the reliability and security for electric power system, temperature supervise on line is a significant and efficient means for working condition supervise of large electric power equipment. This subject is aimed to achieve working condition supervise of high voltage equipment such as high voltage transformer, super generator, high voltage switch etc. At the same time, temperature supervise is crucial to the safe and economical operation and the work life-span of the high voltage equipment. So, it is necessary to supervise the hottest spot temperature of this equipment in order to ensure them to work at their best condition. The information about temperature supervise of high voltage equipment is consulted and analyzed at large near the last forty years. A novel scheme based on optic absorption of semiconductor is proposed, which can overcome the problem of low accuracy and bad reliability in this field. The system configuration of optical and electric portion is given. The major reasons, which cause the low accuracy and bad long-term stability, are the unsteadiness of the optical radiation of the light source and photodetector. An optic-feedback circuit is designed to adjust the drive current of the optic source according to the optic power radiating from the light source. And we get the more steady optic power then before. A reference light source is added in the system. The measurement optical signal and the reference optical signal are coupled into the same optical fiber, and transmitted into the electric signal by the same photodetector, therefore the effect of the photodetector drift to the measurement optical signal and the reference optical signal are coincident. A unique signal pick-up circuit is designed, which can automatic track the measurement signal and the reference signal respectfully, even they are submerged by the noise, and the noises caused by the background light and the photodetector are removed. A higher SNR is gotten. Furthermore, watchdog circuit and software anti-interference measures are designed also. The working steadiness of system is buildup further. The experimental result shows that the system we designed can achieve the following properties: the accuracy is approximately ? 0c over the range covered; the resolution 0.1 0c, respond time is about lms. Furthermore, this system is insensitive to fluctuation of the light source intensity, fiber losses, and photodetector drifts.更多还原