Mechanical Cryocooler Research Of Electromechanical Coupling Driving Characteristics

In the field of aerospace,cryocooler with its small size,light weight and high stability become an important part of the infrared detector components,cryocooler drive circuit output harmonic characteristics of cryocooler performance and the overall electromagnetic compatibility((Electro Magnetic Compatibility,EMC)is larger,the influence of the indirect impact on high resolution camera imaging system stability.During engineering practice found that there are certain Harmonic drive circuit output performance,define the output voltage Total Harmonic Distortion(Total Harmonic Distortion,THD),to cause a decline in drive signal distortion,drive efficiency and so on.To solve these problems in this paper,the cryocooler drive circuit for the following several aspects of research:First of all,based on the related theory of circuit theory to analysis the output harmonic of drive circuit,stidied the optimization of filter method and the bootstrap circuit optimization method.The study found that the drive circuit harmonic produced mainly by the bootstrap circuit performance,the influence of drive circuit of harmonic filter effect is influenced by filter performance.Thus reduce output drive circuit of THD methods in order to reduce the harmonic of bootstrap circuit of harmonic filter,filter effect,so the research mainly for the filter and bootstrap circuit optimization.Secondly,the use of the software can improve the speed and accuracy of the thesis.Research using the Matlab Simulink module of the filter,Simukink peculiar POWERGUI harmonic analysis can be performed to the driver circuit module,through the simulation model of drive circuit and output THD and waveform research can guide filter design with theoretical analysis and experimental verification at the same time;The research of bootstrap circuit introduced the ANSYS software,by Simplorer to practical circuit modeling,combining the experimental study of bootstrap circuit.Then,the study on the filter from the design method and the device L and C the output affects.Filter design using cut-off frequency method,the advantage of cut-off frequency method is according to the cutoff frequency to design a set of filters,more easy to optimize.Research on the effects of L and C are introduced to the device filter transfer function and plot,the final combined with experimental verification,the results of the study the optimization of filter provides support;Bootstrap circuitresearch mainly for the research on the laws of the resistance and capacitance parameters selection,through the simulation and experiment can determine the optimal values of resistance and capacitance.Finally,through the research on the rules of the design of the filter parameters is obtained,through test drive circuit output Uthd < 3%,THD content is greatly reduced,so as to verify the rationality of design;Studies on the bootstrap circuit of capacitance and resistance value are analyzed from various angles,worked out the capacitance and resistance value of law,through the test drive circuit output Uthd < 3.1%,the optimized bootstrap circuit output waveform distortion significantly decreased;Drive circuit for the optimization design,through the test the optimized drive circuit output Uthd < 2.2%,the efficiency increased by 5%,all aspects of performance are greatly improved,so as to verify the rationality of the design.