The Design And Application Of High Voltage Pulsed Power Marx Supply

With the development of science and technology, high power microwave devices have been used not only in military affairs but also in civil facilities. Gyrotron, one of the high power microwave and millimeter-wave sources, is mainly applied in millimeter-wave radar, jammer and civil communication. It is important to research the stable power source of gyrotron.Marx generator is one of the earliest power devices utilized in high voltage test. Recently, with the advancement of pulsed power technology, Marx generator has been used in high power system with the advantage of simple theory and topology.The main research target is demanding gyrotron’s working conditions: high power, long pulse, rectangle waveform and high repetitive frequency. The output voltage is 70 kV, the output current is 15 A, the frequency could be changed within 2k Hz, the pulse width could be changed in 200 us and the power capacity is up to hundreds kW level. Because the traditional Marx generator has bulky size, high cost and not good enough stability, it could not be adapted to the gyrotron source. In this thesis, it uses all solid-state devices to constitute the Marx topology. The solid-state devices have the advantage in high repetitive frequency, good stability, low cost, and low volume to satisfy working conditions.In this thesis, according to the Marx generator’s theory, charging in parallel and discharging in series, the solid-state high pulsed power Marx modulator has been designed for the source of gyrotron. With the analysis of all parts of the Marx modulator and the reference of many research in C hina and overseas, four parts have been designed. There are main circuit, compensation circuit, IGBT driver and insulation circuit and FPGA control circuit. The computer calculation and simulation in all parts have been done. At last, the solid-state Marx modulator has been made and the test of all parts has been done. Then the simulation results are identical with the test.This Marx modulator has a simple structure and low volume. Solid-state device is easy to change and there is no big transformer and insulating oil. Therefore, it has low cost and easy installation and maintenance. The solid-state Marx modulator uses the array topology which utilizes 11 cells to construct a 10 kV pulse power board. The input voltage is 1kV. One redundancy cell in one board is achievable. 7 main boards connect in series to 70 kV output voltage. The Marx modulator takes two IGBTs in series as the controlling switches with the IGBT series technology. This design uses the magnetic coupling driver and optical coupling insulator to drive many series of IGBT switches. For the demand of synchronous multiple driving signals, it takes FPGA through optical fiber to send driving signals. The compensation circuit has a similar topology with the main circuit. Using the ADC sampling data feedback from the output voltage, the FPGA core processes the data to send the driving signal to control the IGBT switches so that the output waveform is almost rectangle with the self-adaptation compensation.