Wire And Cable Insulation Detection Technology

With the development of electrical engineering and the further demand on the service reliability and safety of power systems, the insulation monitoring technique has been paid much attention, at the same time, advanced methods and devices has been in constantly emerge. Electrical wire and cable are the most regular among all kinds of power equipment, and they also have great probability of insulation fault. In our country, the insulation monitoring techniques for high-voltage cable are paid more attention than for low-voltage wire and cable. This thesis focuses on the research and development of the insulation resistor measuring for low-voltage wire and cable. The first part of the thesis has a review-like character. It makes a brief introduction of the characteristic of dielectric, and than the mechanisms of insulation ageing and the circuit model are introduced. Some methods for insulation monitoring are also analyzed based on the circuit model. The second part is discusses the design of the digital megohm meter based on single chip processor in the aspects of both hardware and software. Further more, the use of additive method for on-line insulation monitoring in low voltage network is presented in part three, and it was proved by software simulation.In the end of the thesis, a summary is presented and some suggestions are forward to improve the techniques of insulation monitoring for low voltage network.