Data Collecting And Transmitting Of Cable Fault Monitoring Based On Lab VIEW Platform

Power cable, with various advantages of safe, reliable, hidden and beautifies the city layout, gets more and more widely used in the current power system. However, it will also fail because of various factors in operation. In order to improve the reliability of power supply it is very important to eliminate breakdowns quickly. At present, traveling wave method is widely used in power cable fault location, of which reliability is not affected by fault types in theory. The traditional high-speed data acquisition system cannot meet the transient changes in voltage, current traveling wave's requirements, and is difficult to achieve accurate location test of faults in traveling wave fault location. In this paper, a multi-channel data collecting and transmitting system of cable fault monitoring is designed with NI Lab VIEW platform, using the advantages of high-speed PCI bus and the PCI6221 data acquisition card.Firstly, this paper analyzes the types and causes of cable fault, and demonstrates the feasibility of design of the data collection and transmission system based on Lab VIEW for cable fault monitoring. Then it explains the development of virtual technology, which further proves the feasibility of this system. For better identification of fault signal, wavelet transform is used, and realized in virtual instruments. The theoretical feasibility is proved by the simulation.Secondly, the designing and application of the hardware and software of collecting and transmitting system of cable fault monitoring, according to cable fault transient signals, are performed in this paper. Hardware includes: an integrated current transformer and I/V conversion signal conditioning circuit mainly composed of amplifier, the data acquisition card and PC. Software designing includes: (1) log in, initialization, parameter configuration; (2) data collection: including sample rate, sampling points, sampling number of channels, sampling methods and other online settings; (3) failure alarm; (4) data storage: real-time collected data will be stored to access database for later data query and analysis; (5) data processing; (6) waveform playback; (7) historical inquiry, etc.Finally, the cable fault test circuits are designed, and are connected to data collection and transmission system of cable fault monitoring. Experiments show that the system operations are reliable and continuous. Data collection and transmission basically meet the requirements; the system provides a great amount of data for further fault location.