Research On The Measurement Of Arc Temperature In The Low Voltage Contactors

Low-voltage AC contactor is an important component in low-voltage electrical appliances. It is widely used in all departments as a basic kit component. When low-voltage AC contactor is closed or breaking electric loops, electric arc will be generated between the contact terminals. Once the arc of low-voltage contactor reaches high temperature during arcing, the attributes of low-voltage contactor will be greatly infected, the reliability will be down-graded, and the useful life will be shortened. When high voltage circuit breakers are broken, temperature distribution and variation of the interval, between fixed contact and moving contact, directly influence medium recovery characters. How temperature distribution and variation in this process are understand accurately has important influence to improving the circuit breakers'design and obtaining better breaking capacity.Arc can be captured by the acquisition system successfully, the design of the system is reasonable, performance is credible and the system has good application prospect. With the application of the digital processing technique, the improvement of image quality is achieved successfully. Image with clear edge and good contrast is achieved, and gray-scale value extraction is made for next step.Based on the spectral temperature measurement, the arc radiation image is obtained by CCD camera in this paper, which is processed with digitalized treatment. Finally the three colors RGB of the digital matrix was obtained. The RGB value can be analyzed by the method of colorimetric temperature measurement, the corresponding relationship between the temperature and gray level can be established. The image histogram of the arc is analyzed in our work and the variation of isotherm and arc core can be detected by defining the various temperature boundaries through high frequency signal components comprising edges and outlines of arc images. Meanwhile, the areas of different temperatures are defined by the Pseudo-color Technique. Eventually, a dynamic 2-D thermal field can be obtained by the images of arc, which is a feasible method for the measurement of the temperature of the arc.