Study On Traveling Wave Acquisition Technology Based On PCI Bus

As a part of the key project of the Science and technology in Shanxi Province,the intelligent fault prediction and location of power cable, the main task of this paper is the data acquisition technology applied in the online power cable fault diagnosis system based on the PCI bus. That is to implement the acquisition, transmission, storage of traveling wave signal. The system tries to find the fault point by analysing the value of sample current and voltage and calculating the exact time of fault traveling wave arriving the test points. With the development of computer, microelectronics, communication technology, the emergence of virtual machines has changed the traditional equipment of concept model and structure. As the development platform of virtual instrument, LabVIEW is widely used as the core technology in the system of data acquisition and control system. The online acquisition of transient traveling wave signals and the processing of power system have become possible by using the technologies.Firstly, the cable fault diagnosis methods are analysised and summarized, and the characteristics of traveling wave signal are given. In order to playback the original signals and avoid the wave distortion, a high-speed data acquisition system is designed by using the PCI bus based on the characteristics of traveling wave. The sampling frequency is up to 35MHz. PCI(peripheral component interconnect)bus transmission rate is higher than the traditional system bus transfer rate. The transfer speed of 133MB per second effectively overcomes the bottleneck situation of the traditional bus's highspeed data transfer. This makes the data acquisition and transmission with highspeed and realtime possible.The function and technic of dada acquisition system was put forward based on all module of the composition of data acquisition system and PCI bus protocol and electrical rules. The task includes the front signal conditioning, the core hardware of data acquisition card and development, collection, coding, DMA transfer and designing the Program of VHDL language through the PCI State machine. The system completes the software interface development of LabVIEW based on DLL library, simultaneously, analyses the data transmission of the PCI9054 interface chip, and completes the data transfer, and storages in the host computer. Finally, the acquisition system is tested. The experiment proves that system is feasible and stabe. However, there is still some deficiency in the the system in the actual motion. Also, some suggestions about how to improve the performance of the system are given. This paper provides a solution for data acquisition of intelligent fault prediction and location of the power cable.