Generation And Characteristics Of High Power Short-pulse Based On Semiconductor Switch RSD

RSD(Reserve Switching Dynistor), a new high-power semiconductor device, is a preferred candidate for the switch applied in the pulsed-power apparatus. However, some problems, which confirm to the generation of short-pulse based on RSD, are pressing to solve. This paper aims at solving several problems concerning the generation of short-pulse, including the triggering of high-voltage RSD, the magnetic pulse compression, the measurement of short-pulse, and so on, because such researches are crucial to the generation of short-pulse based on RSD.Two projects of triggering high-voltage RSD, named resonant triggering and transformer triggering respectively, are provided in this thesis. The resonant triggering is designed based on the principle of RLC circuit. The key of this project is to solve some problems of thyristors connected in series, and to choose parameters of triggering circuit, including capacitor, inductor and cross-area of magnetic core.Resistors are parallelly connected with thyristors to realize voltage sharing, and capacitors are parallelly connected to realize synchronous turn-on. Two projects of synchronous triggering thyristors are introduced. One is that parameters of all parts in the resonant circuit are the same, another is that triggering signal is distributed to all thyristors by a transformer, which can assure the consistency of triggering signals. An initial capacitance of the resonant circuit was chosen according to the current rising ratio and the need of critical triggering charge required by RSD. In PSpice, the optimal inductor was obtained according to the initial capacitance, in turn, the optimal capacitance was obtained based on the optimal inductor. The cross-area of magnetic core was calculated at the same time.The transformer triggering is designed based on two functions of saturable transformer: rising up voltage and saturable magnectic core. Two RSDs are triggered by the transformer. The key element of this method is saturable transformer, which is designed by the Magnetics Designer and validated by circuit simulator IsSpice4.By comparing two projects and a result is obtained that RSD below 20kV should be triggered by resonant circuit, and a higher voltage is preferred to be triggered by the transformer.The above research provides theoretic and technical support for solving the triggering of high-voltage RSD.Magnetic switch plays an important role in short-pulse technology based on RSD, acting as not only the isolator between main circuit and triggering circuit, and also elements for magnetic-pulse compression circuits. However, there is an error for voltage-second product of magnetic switch between experiment and calculation. A finite element software ANSYS is exploited to analyze the magnetic field of magnetic core subjected to short-pulse. Result shows that a majority of magnetic field focus on surface of magnetic core, whereas minority on interior, which results in the reduction of utilization efficiency of magnetic core. The principle of magnetic-pulse compression is analyzed, and the parameters of a magnetic pulse compression for high-power laser are designed.The performances of RSD including the time of voltage fall, di/dt, and handling ability of peak current are tested through experiments, at the same time a semiconductor simulator is assisted to analyze these performances.Aiming at problem that the waveform outputted by self-integrating Rogowski coil often distorts, a numerical method is applied to deeply analyze the origin of distortion, and subsequently a circuit is designed to reconstruct the measured current. Experimented result shows that the method is practical and effective.The basic equations for the RSD are derived through the semiconductor theory, and a physical model of RSD is constructed. In this model, the reversal injection process of RSD is under pnn+ diode operation and forward conduction process is under pin diode operation. Based on a method that a diode can be treated as alterable resistance, an Analog Behavior Model(ABM) act as the key element of PSpice subcircuit of RSD, and the expression of ABM is deduced and fitted from physical model of RSD. Experimental result shows that the physical model and subcircuit model are both right.