On-line Monitoring About Underground Power Cable Insulation Based On The DSP

This article focuses on the underground cable insulation aging on line monitoringmethods and how to determine the earth fault slip of these two aspects of the study.Underground cable line monitoring of insulation aging cable insulation can be achievedreal-time monitoring of the situation, Aging of cable insulation can be more seriouswhen the early warning, Timely replacement of the cable to eliminate the hidden faults.In addition, when the cable earth fault occurs to determine which branch and power offit in order to repair the broken branch.This article uses the method of low-frequency current to achieve monitoring of thecable insulation. Low-frequency current method, in theory, can better realize thereal-time monitoring of cable insulation. Low-frequency current law has been a problemin the small current signal is extracted.In terms of hardware design with a high sensitivity of the Hall current sensor tocapture low-frequency signal, AD conversion chip with high-speed high-precision toconvert the analog to digital. DSP powerful signal processing capability to providehardware-based signal extractionOn the software design by Fourier digital filtering algorithm to accurate extract thesignal. For the Fourier algorithm, the article use matlab to do some simulation, andsimulation of various kinds of interference.In view of the principle of low-frequency current law, it can determine the functionof fault branch. Article on this side doing some simulation with the absence of highvoltage.Computer simulations and some experiments confirm that the design can be a goodsolution to the current low-frequency small signal current method difficult problem toextract.The insulation of underground cables to achieve real-time monitoring. Inreal-time monitoring of the cable insulation at the same time, low-frequency current lawalso enables the cable to determine the choice of ground fault branch characteristics.Finally, the article gives the overall design of the circuit diagram and chip supportingthe programming ideas, the overall completion of the design ideas and implementationwork.