Electromechanical Fuze Anti-electromagnetic Interference Analysis And Experimental Research

The rapid development of electromagnetic weapons and the electronization and intelligentization of the weapon systems have caused the electromagnetic interference in the battlefield environment of the modem war.This paper took an electromechanical fuse as the object of study,through the numerical simulation of electromechanical fuse with missile under strong electromagnetic field,analyzed the electromagnetic field coupling law and the electric field distribution inside electromechanical fuse;researched the damage mechanism of typical semiconductor under pulse voltage;studied the interference of the simulating fuse control circuit under strong electric field radiation.The specific content of the work is as follows:Based on one electromechanical fuse,analyzed the working principle,and built the simplified model of missile,fuse and electronic circuit.Applied the simulation software HFSS to simulate the effect of the fuse materials,surface hole or penetrating wire,and obtained the shielding effectiveness change rule of ftuse and the distribution of the electric field intensity in the fuse cavity,and analysed the results.The simulation results show that fuse materials and surface opening hole have little effect on shielding effectiveness of fuse,but penetrating wire leads the decrease in shielding effectiveness and makes large number of electromagnetic energy into the fuse,and the electric field intensity around the wire is high.First,according to the electric field intensity in the fuse,analyzed and calculated the voltage of the coupling to the circuit.Then established the 2D simulation model of diode and NMOSFET,and simulated the process of the pulse voltage injection of diode and NMOSFET,and analyzed the action process from the aspects of electric field intensity,current density,electron concentration etc.The simulation results showed that applying of reverse pulse voltage led to big current concentration appearing in the diode due to the second breakdoxwn,the current location had concentrated heat,it may cause thermal damage and diode failure.The simulation results also showed,the drain voltage injection caused the PN junction of the drain and substrate of NMOSFET avalanche breakdown,and caused electric field intensity and current density concentrating on the same PN junction,which made the heat concentration to lead to final damage.And the short channel NMOSFET in the non working state,caused the accidental conduction because of the pulse voltage on the drain,.Made the radiation experiment of high electric field on the simulating fuse,and studied the simulating fuse anti-interference condition of different materials and different electronic devices.Combined with the results of the experiment and the analysis of the simulation of the third and fourth chapters,it shows that the microprocessor or conducting controller of fuse control circuit were subject to certain interference under strong electric field irradiation,semiconductor devices temporarily fail or be slightly injury,it makes the resistance of circuit system become small which is similar with circuit short-circuit phenomenon.So fuse system needs to strengthen the electromagnetic protective measures.So the method of improving the anti electromagnetic interference ability is proposed in the design of fuse from two aspects of shielding interference source and improving the anti-interference of the circuit.