A new method for measuring the speed characteristics of high voltage circuit breaker based on machine vision algorithm

The speed characteristic of moving contact is vital to the high voltage circuit breakers. But due to the contacts of high voltage circuit breaker are completely isolated by arc chamber, the common measurement methods have some disadvantages. In this paper, a new method for measuring the speed characteristics based on machine vision algorithm is developed. This noninvasive method just needs to draw or mount some colorful markers on the surface of the moving parts as the movement reference points. The moving tracks of these reference points will be recorded by high speed camera and identified by the machine vision algorithm automatically after processing the videos. The displacement curve of moving contact can be obtained finally, so as the speed characteristics. In the measuring process, the first step is the data acquisition procedure, in which, the marks are set and their movements are recorded by high speed camera. The second step is the main part of the system. Through utilizing the technic of color discrimination which is implemented with machine vision algorithm, the relative coordinates of every mark in every picture can be calculated. Finally, the speed characteristics of moving contact can be calculated using these coordinates. The experiments have been carried out with a 252kV SF6 circuit breaker and the experiment result presents that the characteristic measured by the method proposed in this paper is precisely compared with the other displacement sensor. This method doesn't require any additional fixtures and is more convenient than traditional method.