Health Status Evaluation of Low-Voltage DC Circuit Breaker Based on the Morphological Characteristics of Arc Plate

In the breaking current process, low-voltage DC circuit breakers inevitably generate arc. Arc ablation will seriously affect the health status of circuit breakers. Therefore, this paper proposed a health status evaluation method of low-voltage DC circuit breakers based on the morphological features of arc plate, by analyzing the arc erosion traces. Firstly, carry out the cyclic operation test of DC circuit breaker, and collect the 2-D morphology image of arc plate at a certain interval. Then, the image processing algorithm is used to visualize the arc guide image. The key morphological feature parameters are extracted: 1) Distinguish the color difference between the arc track area and other areas through the threshold segmentation method. Thus, the arc track area is extracted and its area is calculated as feature h1; 2) Extract the material loss area of arc plate after ablation based on un ablated image. Thus, the loss area is calculated as feature h2. Finally, according to the degradation traj ectories of features h1 and h2, they are divided into linear degradation features and nonlinear degradation features. This paper established a health status assessment model using both segmented fitting and σ principle. Through example verification, the accuracy of this model is as high as 100 %. By using the morphological characteristics of arc plate, the purpose of characterizing health status of circuit breaker is achieved.