The Research Of High Voltage Nanosecond Pulse Measurement System Based On Optical Fiber Transmission Technology

Electromagnetic pulse (EMP) has many characters such as steep rise edge, narrow width, and wide frequency band, etc. It can influence or destroy electronic parts, circuits and equipments through various coupling ways. Thus the theories and techniques of EMP and its engineering protection are still one of the hot topics in research of the world. The status quo at home and abroad of high-voltage nanosecond pulse measurement technology and the fiber optic transmission technology in the measurement were summarized in this paper, the coaxial cable transmission error was analyzed, research on fiber optic transmission technology of high-voltage nanosecond pulse measurement system was done. The main results and conclusions obtained from those researches are listed as following:The optical fiber transmission measurement system was designed. System components and the principle were described. The system consists of the pulse generating device, voltage divider, light emitting port, optical fiber, light receiving port and oscilloscope. Focus on developing the light emitting port and receiving port, the photoelectric conversion circuit was designed to solve pulse signal conversion problem. Multisim circuit simulation software was used for circuit simulation and parameters were integrated, simulation results show that the transmission has good performance. Based on the simulation, the prototype was produced, the function generator was used to test circuit performance on the prototype, solving the problems of waveform saturation and distortion by setting the wrong quiescent operating point, circuit parameters were debugged, part of the devices were replaced, the output waveforms take on good performance. The experiment platform was set up, and the photoelectric conversion prototype was applied to the high-voltage pulse measurement system. Impedance matching, electromagnetic shielding and other issues were disposed through the experiment. Contrast experiments have been done on the coaxial cable transmission measurement system. Experiments show:the the produced system has advantages such as:high measuring precision, strong anti-interference ability, long distance transmission with no waveform distortion, the effect is obviously better than coaxial cable measurement system.Because of the nonlinear error of the resistor divider in the optical fiber transmission measurement system and losses of optoelectronic devices which making the measurement system with deviations, the concept of waveform reconstruction was proposed. By analyzing the waveform reconstruction theory and comparing advantages and disadvantages of the modeling method, the mechanism analysis and experimental modeling combined modeling method was selected for the measurement system, the mathematical model of the differential equation method was chose, and the selected model order determination principle was given.The waveform reconstruction theory was applied to the optical fiber transmission pulse measurement system, the method of differential equations filter was used to reconstruct the waveform. Through the preparation of compensation software, the input and output signal data was obtained and imported to the software, the mathematical model of the measuring system was identified, after completing the calibration of the measurement system, measured pulse waveform was reconstructed by computer, the results show that the waveform reconstruction were in accordance with the original input, achieving the expected effect.