Research On The Measurement And Control System Using On 15kV Nanosecond Pulse Generator

Pulse power technology not only plays more and more important role in military and high-tech research, but also exhibit good application potential in many fields,such as industry, biomedicine and environment protection and so on. Therefore in the recent years pulse generator has been focus at home and abroad, but there were rarely reported about intelligent controlling pulse generator, so it has vital scientific significance and the application value to develop nanosecond pulse generator with intelligent control. This thesis developed a 15kv nanosecond pulse generator with intelligent control based on mesearing nanosecond pulse voltage and current, moreover combining intelligent voltage adjustment and fault protection.Based on analyzing the principle of capacitance divider and Pspice software, the two operating modes of capacitance divider had been analyzed theoretically and simulated, moreover the elements which effecting divider's response characteristics had briefly been introduced. According to the theory that capacitance divider was made on th coaxial cables, the capacitance divider which had high performance was researched and designed. This novel divider overcame the traditional problems that high inductance in the high tension lead and high joint inductance between high-voltage capacitor and low-voltage capacitor. By through step response tests and linearity degree experiments, it had found that the mesearment performance was good and the divider ratio was unchangeable, furthermore the real divider ratio was 382.2 whose error was 3.94% compared with the theoretical ratio and its response time was 15.96ns, moreover the biggest error was 5.54% on the linearity scale curve. According to the theory that the resistance divided voltage, the resistive divider which had good performance was developed. From step response tests and linearity degree experiments, it had found that the real divider ratio was 989.8 whose error was 1.02% compared with the theoretical ratio and its response time was 14.11ns.On the basis of establishing the equivalent circuit with concentrated parameters, the amplitude-frequency characteristics, sensitivity, amplitude response under square wave current, the elements which effecting the mesearment persormance were all annlyzed. Using Pspice software the amplitude-frequency characteristic of coil under the different number of turns and different value of integral resistance were simulated, and then combining with the design principle and design requirements the structure parameters, turns and integral resistance were determined. According to calibrating sensitivity experiments, step respons tests and linearity degree experiments the real sensitivity was 244.2A/V whose error was 2.32% compared with the theoretical ratio and its response time was 19.6ns,moreover the biggest error was 3.42% on the linearity scale curve. From the AC small signals scanning experiments, its real operating frequency band was [1 0 kHz～50MHz] which was approximately same as the simulation results.The keys of intelligent voltage adjustment system were digital potentiometer MAXIM 5455 and linear photoelectric coupling LOC110, and application programs were compiled using Visual c++6.0 which was graphical compiling language, furthermore the communication between exterior and computer was carried out by ICP7044D module, in consequence the output value of high voltage DC power supply could be regulated with computer. Taking voltage comparator LM360 and RS flip-flop circuit as the core, furthermore combining with shrot-circuit fault signals and HVDC power fault signals, the function was implemented that fault protection, and after resetting the pulse generator could be normally started again. The general software flow chart of control system was detailedly introduced.According to the experiments for mesearment and control system of the 15kv nanosecond pulse generator in the laboratory, the whole mesearment and control system had high performance, moreover it could improve the generator's stability and make generator's operation more intelligent and easy.