超高压输电线路铁塔静态图像遥测技术应用(英文)

STILL IMAGE REMOTE MONITORING UPON EHV POWER TOWERS

在绝缘子遥测系统的基础上,提出了基于短信息服务(SMS)方式的超高压铁塔上静态图像监测技术方案,对铁塔塔身构件、绝缘子串、线路覆冰等状况进行静态图像监测,用户可随时获取各级铁塔的现场图像信息,分析判定故障,并依此制定相应的检修策略。根据监测图像及传输信道的特点,提出了针对差值图的类JPEG压缩算法;采用基于期望压缩比的量化模型来提高压缩效率;通过对环境光强变化模型和绝缘子闪络模型的图像压缩实例分析,压缩后的数据量降至数十字节至数百字节,通过一帧或数帧SMS即可传输。文中论及的技术可应用于电力系统其他设备的远程图像监测,为电力行业由计划检修过渡到状态检修提供了科学依据。

Based on the telemetry system for polluted insulators developed in our previous research, a stili image monitoring technique adopting Global System for Mobile Communication (GSM) Short Message Service (SMS) data transfer technology is presented to rnonitor the state of extra-high voltage (EHV) power towers, insulators, and ice-covered transmission lines. Users can obtain the scene images of the EHV power towers at any moment so as to analyze the equipment status and work out maintenance schemes. According to the characteristics of the monitoring images, a JPEG-like algorithm is specially proposed for the difference image to achieve high compression ratio. A quantization modei based on expected compression ratio is adopted and improved. Two instances--variation of brightness and flashover of insulators, are discussed. Our experiments show that the image data are compressed to tens of or several hundred bytes, which suggests that only one frame or several frames of short messages be needed to transmit the data. The techniques described in this paper can be used in other power system equipment for stili image monitoring and can provide scientific basis for state maintenance.