Investigation Of A Repetitive, Modularized Induction Voltage Adder

Military and industrial applications have stimulated intense interests in the area of pulsed power technology towards the systems with high average power, high repetition rate, solid-state characteristics, and compact structure. The solid-state pulsed electron beam accelerator based on the technology of induction voltage adder (IVA) investigated in this dissertation is an important candidate in this area. In this dissertation, a 10-stage, repetitive, modularized IVA with an output voltage of 500kV is investigated based on the detailed theoretical analysis, circuit simulations, and experiments. A rolled strip pulse forming line with an impedance of 3? and pulse duration of 230ns is fabricated as the voltage drive source to study the response characteristics of the induction cell. Preliminary experimental investigations are carried out on both the single pulse mode and the repetitive pulse mode. These efforts are instructive for the further developments on the solid-state pulsed electron beam accelerator. The detailed contents and innovative work are as follows.1. A novel solid-state pulsed electron beam accelerator based on the technology of IVA with the advantages of high average power, high repetition rate, solid-state, and long lifetime is proposed. It comprises primary energy system, pulse transformer, pulse magnetic compression, rolled strip pulse forming line, and IVA. The design of the IVA is introduced in detail. The parameters design and circuit simulations on the other sub-systems are also carried out.2. The technology of the IVA is investigated theoretically in detail. The lumped element model and distribution element model are given respectively according to the electrical transit time of the IVA. When the electrical transit time of the IVA is comparable to, or even longer than the pulse duration, the distribution element model can be useful. Otherwise, the specific model will be simplified to a lumped element model. In the lumped element model, the analysis is split into three parts, namely the responses to the leading edge, the flat top, and the trailing edge of the pulse. In order to analyse the response of the induction cell to a rectangular pulse, the method of Laplace Transform is employed. Some principles in the design of the induction cell are given referred to the analysis. In the distribution element model, the transmission line theory is used to the analysis on both the driver-matched and load-matched IVA. At last, a two-stage IVA is fabricated and experiemental investigations are carried out to verify the theoretical analysis.3. Based on the results of the theoretical analysis and the characteristics of the pulsed power source of the IVA, a 10-stage IVA with the output voltage of 500kV is designed. The dimension of the IVA isΦ0.58 m×2.2 m. The induction cell is drived by a single feed port and contains an azimuthal transmission line in order to equally magnetize the metglas cores. In the outer region and central transmission line of the cell, the insulation medium is transform oil. In the cores, the insulation medium is a combination of oil and solid films. The volt-second product of the cores in each cell is about 10mV·s. The distributions of the transient electric fields are calculated with the method of finite-difference time domain. The equivalent circuit models of the single induction cell and 10-stage IVA are developed via the PSpice software and detailed simulations are performed based on the model. The measurement system is also fabricated, including the resistor divider, the capatitive divider, and the Rogowski coils.4. The theoretical analysis, electric field simulation, and experimental investigation are carried out on the rolled strip line. Two rolled strip lines with an ouput impedance of 1.5? and pulse duration of 200ns are fabricated with different methods. The distributions of the electric fields and the output voltage waveforms of the two strip lines are compared. The results show that the output voltage waveform of the strip line rolled with 3 copper strips and 3 insulation layers is relatively better with fast leading edge and smooth flat top. In addition, to study the response characteristics of the induction cell, a rolled strip pulse forming line with an impedance of 3? and pulse duration of 230ns is fabricated as the voltage drive source.5. Preliminary experimental research is carried out on the induction voltage adder drived by the rolled strip pulse forming line. Experimental investigations on the single induction cell, 2-stage IVA, and 4-stage IVA have been carried out. The experimental results show that the induction cell can transfer the input pulse with few distortions, and the 4-stage IVA realize the voltage addition with a current efficiency of about 80%. When the charged voltage of the 4-stage IVA is about 30kV, the pulse with duration of 230ns is abtained on the 50? load. Repetitive experiments are also carried out on the 4-stage IVA with the charging voltage of about 25kV. The sequence of 20 pulses at the frequency of about 3Hz are obtained, which is well repeatable...