基于机器视觉的高压断路器速度特性测量方法研究

Study on Measurement Method of Speed Characteristic of High Voltage Circuit Breaker Based on Machine Vision

分合闸速度特性是高压断路器的重要特征参数,其大小直接影响高压断路器的工作性能。针对采用常规传感器测量高压断路器速度特性时普遍具有的安装固定困难、影响断路器特性等缺点,文中提出了一种基于机器视觉的速度特性测量方法。此方法通过在高压断路器运动机构表面设置参考标记,使用高速相机在断路器动作时对其进行视频图像采集,经由机器视觉算法处理后,识别得到标记参考点的运动轨迹,进而获得高压断路动触头的速度特性。以12kV永磁真空断路器为例进行了实验,结果表明,此方法可取得与高精度位移传感器较为一致的结果,测量误差小,能满足高压断路器速度特性测量的要求。此外,此方法无需安装传感器固定夹具,无电压隔离等问题,便于现场测量,测量效率高。

The speed characteristics during opening and closing operation are important characteristic parameters of high voltage circuit breaker, which affect the working performance of circuit breaker directly. It is always difficult to mount a displacement transducer or angle sensor into a high voltage circuit breaker online. Besides, the sensors and its attachments always take negative impact on the mechanical characteristics of circuit breaker. Aiming at solving those problems, this paper developed a speed characteristics measuring method based on machine vision algorithm. This non-invasive method only needs to set some color marks on the surface of some moving parts as the movement reference points whose movement keep in accordance with the moving contacts of circuit breaker. The moving tracks of reference marks are automatically identified through processing the video of circuit breaker operation recorded by high speed camera.Then the speed characteristics of moving contact can be obtained, based on machine vision algo- rithm. Experiments have been carried out with a 12 kV vacuum circuit breaker, the result shows that the characteristic curve measured by this method is precise compared with high accuracy displacement sensor and it meets the re- quirement of speed characteristic detection. Moreover, this method doesn＇t require any additional fixtures and is more convenient for on-site measurement than traditional measuring method, without the necessity for high voltage isolation.