| Pulse power supply is one of the applications of pulse power technology.Because of its high density and fast release of compressed energy,it is widely used in scientific research,industry,biomedicine and other fields.Generally speaking,pulse power applications are specific,but with the development of research,more comprehensive requirements have been developed in terms of voltage and current,up and down edge and low impedance characteristics.Especially in the biomedical field,low impedance characteristics make pulsed current more important.Therefore,Thesis develops a high voltage and high current pulse power supply with high output voltage,high output current and adjustable pulse frequency and pulse width.Through the research and comparative analysis of the realization mechanism of pulse power supply,a high-voltage high current pulse power supply consisting of an adjustable DC power supply circuit and a Marx type pulse generator circuit has been developed.In the study of the primary DC adjustable power supply module,a power scheme combining the step-down buck circuit and the pulse-width modulation circuit in FCCM operating mode was designed.It is given in the text the specific design of the prerectifier filter circuit,power output circuit,pulse width modulation control circuit,and voltage and current sampling feedback circuit is given,and the specific design method for the calculation and selection of core power devices is given.In the pulse generation circuit,the designed constant voltage current limiting charging method improves the charging efficiency of the pulse energy storage unit.The pulse generation circuit is composed of a Marx-type pulse generation circuit as a unit and a cascade superposition structure.This method reduces the internal resistance of the system and improves the low-impedance load capacity.In order to accelerate the synchronization of truncated discharge and inter-pole discharge,a PNP-type gate fast discharge circuit is designed,and an RCD buffer circuit is used as the protection unit of the pulse generation circuit.The influencing factors of the pulse cascade circuit were studied and analyzed by the Pspice simulation software,and the pulse output formula was verified and summarized,which illustrated the feasibility of the scheme.The pulse power supply is controlled by using the FPGA as the main controller,and the pulse output of the power supply system is controlled by writing the PWM control program of the pulse generation circuit.Finally,the prototype of high voltage and high current pulse power supply is built,and the high voltage test environment is explained.The experimental verification of the voltage regulation output of the DC adjustable power supply module under different duty cycles and frequencies and the pulse output of the pulse generator module under different frequencies and cascade operation are carried out.After trial and error,a pulse signal with a maximum output pulse voltage amplitude of 1200 V,a maximum output pulse current amplitude of 50 A,and the maximum rise and fall edges of the pulse output shall not exceed 1us,with a frequency of 100Hz～1000Hz. |
