Research On Protection Method Of Solid-state Marx Generator Under Capacitive Load

Pulse power is increasingly used in industrial fields.As an important means of generating pulse power,solid-state Marx generators have gained widespread acceptance and adoption.However,solid-state Marx generators still have many problems under capacitive loading.In view of this situation,this paper describes the circuit structure of a typical Marx generator,and analyzes three working modes that may occur during the operation of the Marx generator,and presents a simplified circuit model of the Marx generator in three states.Based on the principle characteristics of the basic working mode,the overall operating characteristics of the Marx generator under capacitive load are further analyzed.The transient current is likely to occur under capacitive load conditions,which could result in performance changes or even damage of switching devices and storage capacitors.For this case,the characteristics of the existing protection circuits are summarized,and the advantages and disadvantages of different protection methods are compared.Then this paper analyzes the internal structure and working principle of MOSFET and IGBT,and gives the working characteristics of these two devices.Combined with the working principle and output characteristics of the voltage-driven device,a protection circuit that can respond quickly and does not malfunction is designed.It can easily cope with capacitive load or uncertainty load,and achieves a flexible and variable autonomous limit on instantaneous overcurrent.Under normal conditions,the pulse rising edge steepness of the solid-state Marx is not affected.An ingenious power take-off circuit is also designed,which could take power from capacitors and supply power to the drive circuits at the same levels.The circuit is low in cost,simple in structure,easy to implement.Used in the solid-state Marx generator with a large number of stages,this kind of circuit can greatly reduce the complexity of the system so that the overall reliability of the system is guaranteed.Finally,the actual design method of the solid-state Marx generator is given.In order to verify the feasibility of the design,a physical platform is built for verification.The experimental results show that the proposed driver and its protection circuit can effectively protect the circuit.At the same time,this ciucuit has little effect on the rising edge of the output pulse.Therefore,the overcurrent protection method proposed in this paper has high application value.