Research On Switch Drive Isolation Technology Of Marx Pulse Generator

In recent years,the rapid development of pulsed power technology has become a huge thrust to promote industrial development in fields such as national defense,industry,and biomedicine.As the core device in these different application fields,high-voltage pulse power supplies often require high-amplitude,fast-rising pulse output capabilities.Marx circuit is widely used as the most classic pulse generation topology.During the high-voltage pulse generation period,how to ensure that the semiconductor switches of the pulse sub-modules in the Marx circuit are driven and turned on synchronously under the high-potential floating condition is a great challenge to the development of the pulse power supply.In response to this common technical problem,this paper proposes a multi-switch gate drive power supply system based on a wireless power transmission array,and a high-position floating self-trigger drive technology scheme for semiconductor switches.And cleverly integrated the technical advantages of the two solutions to develop a pulse power supply based on the hybrid drive of semiconductor switches,which effectively solves the problem of high-voltage isolation between the drive circuit of each semiconductor switch and the low-voltage control part.Firstly,based on the single transmitter to single receiver coil magnetic coupling resonant radio power transmission structure,this paper proposes a drive isolated power supply array with multiple interfaces to meet the application requirements of multi switch drive isolated power supply in Marx pulse generator.The mathematical model of multi coil array radio power transmission is constructed,and the calculation method of primary and secondary side compensation capacitance is derived.The sensitivity of output voltage gain,transmission power and transmission efficiency to resonance parameters is discussed.By using Maxwell and Simplorer simulation software,field circuit co simulation is carried out to verify the accuracy of the self built model and the theoretical feasibility of semiconductor switch driven wireless isolated power supply.Secondly,when the number of sub-modules of Marx generator is large,in order to avoid the complexity of the multi-switch drive power supply system of the whole machine,from the perspective of switch passive drive,this paper proposes a switch high suspension self-triggering drive technical scheme without using the dedicated integrated drive IC.By adding high potential self-energizing capacitors among all levels of sub-modules,the high potential floating ground self-triggering drive of each switch is realized,and the number of wireless isolated power supply interfaces is reduced.The gate driving scheme only needs to provide the driving signal of the lowest level sub-module switch,and the switches in other sub-modules can realize high floating self-triggering driving.Taking resistive load and capacitive load as examples,the working principle of the proposed high potential self-triggering drive for solid-state switch of pulse generator is analyzed in detail,and the calculation criteria of high potential energy taking capacitance and drive damping resistance are derived.Then the circuit simulation model is built by PSPICE software to verify the theoretical feasibility of the proposed self-triggering pulse generator structure.The prototype of principle verification with equal parameters is developed.The selection of semiconductor switching devices and the layout design of pulse main circuit are carried out in detail.Finally,the output pulse performance of the prototype under different load types is tested.The test results show that the output pulse amplitude can reach 15.3 k V and the pulse current is about 20 a when 20 level sub modules are superimposed with 800 V DC.The rising time of the output pulse is 40 ns,which fully verifies the theoretical feasibility of the proposed self-triggering Marx pulse generator.Finally,this paper combines the advantages of wireless isolated power supply and self-triggering drive,proposing an all-solid-state switch hybrid drive pulse generation method.In the Marx pulse generator,wireless isolation is used to isolate the power supply for the special integrated driver IC,and the switch high energy self-triggering driver is integrated into it.On the basis of theoretical analysis and simulation,a wireless isolated drive power supply system with six output interfaces is developed.The system mainly includes input inverter voltage source module,transmitting and receiving resonant coil,etc.The power supply system is tested by modules,and the test results are consistent with the theoretical analysis.The power transmission efficiency of isolated power supply system can reach 50%.In order to ensure that the switches can act accurately according to the given parameters and can respond quickly in the face of failure,this paper designs a multi-functional integrated grid drive scheme for three fault conditions,which are the common gate drive undervoltage,short circuit over current of drain source and excessive junction temperature rise,and the design scheme is analyzed and verified in detail.At the same time,in order to realize the programmed control of the output pulse parameters,a control system based on FPGA and PC is built.The control system can realize the flexible adjustment of the pulse parameters,and the running state of the pulse generator can be monitored by high-speed AD sampling.The performance of the developed all-solid-state switch hybrid drive pulse generator prototype was tested.The test results show that the pulse voltage amplitude can reach24 k V and the pulse width can be adjusted flexibly from 200 ns to 1200 ns with 300 ?resistance load,which verifies the feasibility of the proposed method.