The Application Of Power DC System On-line Ring Network Alarm Device And Live Loop Search Device

DC power supply system plays a crucial role in the safe and reliable operation of the power grid. Once the insulation of the DC power system is reduced,it is likely to cause DC ground fault or ring network fault, which may cause malfunction or refuse operation of the secondary equipment. In the event of a complex situation such as high resistance grounding, grounding of the ring network, grounding caused by AC stringing in DC, etc., with the continuous increase of the ambient temperature in the scene, it is more unfavorable for the accurate positioning of the fault grounding point. There are many power supply modes for two sets of DC systems,which cause many reasons for the malfunction of the ring network. Incorrect power supply modes or grounding of the power supply may cause risks to the DC system. It is certified that the ring network fault not only requires a lot of time and effort but also requires some practical experience by the more field practice, thus greatly reducing the efficiency of fault elimination and reducing the DC system security and stability factor.This dissertation summarizes the types and characteristics of earth fault and ring fault of all kinds of DC systems, analyzes and compares the troubleshooting methods and their advantages and disadvantages, and introduces the composition of the on-line alerting device for ring fault insulation. Through the partial pressure sampling, to take isolation and amplification technology, and high-precision AD conversion, and then the voltage signal analysis,processing, and can correctly determine whether the ring network failure and the type of ring failure, the alarm signal output principle of the loop network fault location device is introduced. The device through the DC system into the ultra-low frequency, micro-current signal, and each feeder branch to ground DC signal leakage current judgment, analysis, by simulating the condition of the ring network, the working principle of accurately locating the ring network failure point is finally analyzed. Through the practice of comparison, highlights the ring network fault alarm and positioning device applications on-site work significance.Based on the analysis and summarization of the actual cases on the spot, this dissertation puts forward effective measures and troubleshooting steps, further closer to the actual work, and realizes the purpose of sharing the actual cases with professionals on site, providing the future ring network troubleshooting live,operational methods, but also on the ring network fault alarm and its positioning device in the field of actual application process made a brief description of the actual case on-site have a very good representation of the future investigation ring network fault work has more profound meaning.