The Study On The Measurement Of Lightning Flashover Current For Transmission Lines

The concept of lightning, parameters of lightning current and flashover mechanism occurred in transmission line struck by lightning are analyzed first. The key parameters of measuring devices for lightning current are designed according to related standard trends. On the basis of the conclusion of the available research results at home and abroad , this paper compares measurement methods being used in the practical projects currently, and design the method used to measure the lightning flashover current for the transmission line. According to characteristics of flashover current in transmission line struck by lightning and its measurement requirements, the measurement devices are designed and fabricated. Applied with MAPLAB integrated development environment, data acquisition as well as the bottom software of the serial communications are developed and debugged, and the corresponding measurement data is provided. Meanwhile, over-voltage protection for the system is analyzed relatively, the corresponding SPD is designed, the hardware of the circuit of the system is accomplished, and comparative analyses of results useing different components as well as experimental data are provided.A variety of EMC measures are adopted synthetically during the process of hardware fabricating. The designing of the reliable reset circuit, RAM protection circuits, signal pre-conditioning circuit and protection circuit for system, could keep the whole system working reliability. The development board of MC39i and GPS module are designed and produced applied to debug and develop communication module, and the corresponding test results are given. In terms of software design, the bottom control for the whole system was developed; Relative reasonable algorithm based on wavelet shrinkage for data-processing is designed. And the anti-interference ability of DAQ system was improved, which is emulated with the software of MATLAB wavelet.The data acquisition for analog signal and the communication are tested in the laboratory. And the experimental result indicated that the system is stable and reliable, and the system achieves the appropriate design requirements.