Research On A Repetitive Frequency Pulse Power Current Source

Pulse current source are mainly used in microwave, controlled nuclear fusion, high-power energy generators, bio-medical, preparation of new materials, environmental protection and other fields. It is closely related to dense science and technology and people’s livelihood. Thus, it has become a hot topic of pulse power supply field in recent years. This paper carried in-depth research on the repetitive frequency pulse current source. A program about pulse current width and rising has been designed, which solved problems that pulse current width is not narrow enough and the current rising is not fast enough.The research of pulse power current source system is expanded, which consists of a DC-DC primary power converter, a storage capacitor array and a pulse power discharge topology. The primary power converter uses a buck cascade push-pull circuit, while the pulse power discharge topology uses a main switch at the low end of buck topology, and adds another two switch tubes made up pulse control switches and energy feedback diodes, to generate pulse current.Working principles of buck cascade push-pull circuit and pulse power discharge topology thoroughly are analyzed. The buck converter synchronous rectification program has been studied on energy loss problem of the system. It has a corresponding energy feedback circuit, increasing energy efficiency. System power density and dynamic response are enhanced in all.Parameters of buck cascade push-pull circuit are designed, contain choosing push-pull transformer, power inductor and so on. Small-signal model of circuit is established. And the average current control method is used to achieve closed-loop control. At last, passive compensation network is applied to feedback compensation. The results show that the designed average c urrent control scheme achieved a stable and effective operation of the system.The research of pulse power discharge topology is expanded, analyzing control circuit and selecting inductance and capacitor in detail. The current sampling circuit is very simple and accurate. The hysteresis circuit is real-time tracking of inductor current change, improving the system dynamic response. The control logic circuit uses timing control to make sure each pulse is repeatable. Factors which affect the pulse current width and rising rates are discussed. Simulate pulse power discharge topology, and the results show that it can obtain different widths of the output pulse current at different pulse repetition frequencies.Hardware circuit platform is built which corresponding to each module, and analyzes the experimental results of individual modules and multi-modules. It gets pulse current which the amplitude is 50 A under the repetition rate at 1k Hz, 400 Hz, 100 Hz, 2% duty cycle of the pulse signal. When the repetitive frequency is 1k Hz, the narrowest width is 13μs and the current rise is 46.1A/μs. It achieves frequency repetitive, pulse width narrow, rising slope steep of pulse current source reliably.