Research on thermoelectric characteristics and recognition methods of looseness fault in coal-mine bolted cable joint

The coal-mine bolted cable joints are widely used in electrical connection between the cable and electrical equipment. It´s particularly important to recognize timely the electrical connection looseness fault of coal-mine bolted cable joints. Lots of looseness fault experiments of silver-plated copper cable joint under different loosening state, current and load conditions were carried out with self-developed experimental platform. The temperature characteristics, contact voltage and current characteristics of the loosening bolted cable joint under different conditions were studied. A new looseness fault identification method based on current energy entropy and Probabilistic Neural Network (PNN) was proposed. The multi-resolution analysis of current signal was conducted by using wavelet transform and the current energy entropy used as a typical feature parameter of electrical connection looseness fault was extracted. The looseness fault can be identified accurately by putting the current energy entropy into a PNN fault diagnosis model. It showed that the method can identify the electrical connection looseness fault of coal-mine bolted cable joint effectively.