Research On Large - Scale Switch Synchronization And Triggering Technology

The capability of directly generating high power pulses with the rise time less than100ns makes the technology of fast linear transformer drivers (LTD) a huge potential dominace in the fields of pulsed power. It has become a research focus in the relevant institutions in recent years. At present, the research on the structure and characteristics of fast LTD induction cavity has been relatively mature, but with the scale enlargement of LTD device, synchronization and trigger of large-scale gas switches has become a bottleneck restricting the development of LTD technology. Therefore, to adapt to the LTD mass switches operation characteristics of synchronization and trigger technology research has important significance and application value. Based on the research status at home and abroad, mainly from two aspects of external trigger and self-trigger technology of large-scale switch synchronization and trigger technology were studied.Firstly, through extensive investigation, this paper summarizes the characteristics and trigger requirements of all kinds of switches used in current LTD device, and proposes the solution of large-scale switches synchronization and trigger technology and ideas. According to the size of the LTD device, this paper puts forward a set of synchronous trigger system solutions based on the reverse working principle of LTD, it is named LTD-trigger by us. LTD-trigger is studied through the working principle, structure and the characteristics of key components. On this basis, respectively, the modeling and analysis of a single trigger induction cavity and multistage series triggering induction cavity have been finished, the LTD-simplified circuit model of the trigger has been put forward In the process of analysis, the parameters of the circuit has deen studied in detail, the main research contents included:loop inductance, magnetic core, the equivalent loss resistance, distributed capacitance and output coaxial transmission line and the load. Through a series of analysis, determine the methods of design and calculation on LTD-trigger parameters which provide the basis for simulation study. The simulation and modeling about the LTD-trigger system have been completed. Based on the transformer model, single induction cavity simulation circuit and the induction cavity simulation circuit in series are established respectively. Through simulation, the number of turns, the primary pulse source, and coaxial cable of the output of LTD-trigger have been studied. Considering the actual load is LTD gas switches, and the performance of gas switches has certain uncertainty, aiming at the uncertainty, this paper studies the working characteristic of the LTD-trigger with the load under different working condition. Simulation results show that LTD-trigger has a simple structure, easy to expand, and characteristics of fault tolerance. At last, the design of corresponding LTD-trigger large-scale switches synchronization triggering system for the existing LTD device solutions is been given.Based on the theory and simulation research of LTD-trigger, a set of small LTD-trigger principle prototype experimental device has been developed. The principle prototype can output high voltage trigger pulses with amplitude of about25kV and the rise-time of about60ns. The design scheme of the small LTD-trigger, system layout, the primary pulse source, trigger system and magnetic cores reset system have been described in detail. On the pulsed magnetic properties of cores, open load output and equivalent switch gap has been considered during the experimental research and related theory analysis. Through comparing with the simulation results, verify the feasibility of LTD-trigger scheme.In the self-trigger technology, based on the LTD-trigger electromagnetic induction principle, two ways have been put forward for realization:grouping induction self-trigger mode and cascade induction self-trigger mode. Grouping induction self-trigger mode and cascade induction self-trigger mode are described and analysed in theory respectively. According to the known experimental results at home and abroad, this paper established the PSPICE model of1MA LTD induction cavity, on the basis of the model, several types of self-triggering induction cavity model are established for simulation research. Through comparison between simulation results, the model established in this paper is correct and can reflect the real working process of the circuit. The simulation circuit of a LTD with60induction cavity stacked in series has been established. The current with rise-time of60ns has been obtained on the matching load through large-scale switches self-triggering, the peak of the current is about1MA. Preliminary simulation proved that ideal output waveform can be got through the self-triggering of fast LTD device.