Research On Design And Optimization Of The Pulsed Inductor For The Pulsed Pump Power Supply Of High Power Laser

The pulsed pump power supply of high power laser is one of the key components of the energy system of the laser inertial confinement fusion facility,using shunt capacitor banks as primary energy storage units.A single power supply usually provides MJ level pulse excitation energy for xenon lamp loads.With the continuous development of inertial confinement fusion technology,the requirements for the output current and discharge energy of pulsed pump power supply have been further improved,which has brought more severe challenges to the design of components in the power supply.The pulsed inductor as a key component in pulsed pump power supply,its performance directly affects the safety and output characteristics of the power supply.The pulsed inductor needs to withstand high peak pulse current in a high-power pulsed power supply.For some inductors,it may also be required to be able to absorb large discharge energy.Work principle and electric circuit of the pulsed pump power supply were introduced firstly.The power supply uses three types of pulsed inductors for different uses,including the protection inductor,the ballast inductance and the preionization inductor.Based on the nonlinear load characteristics of the large-size high-pressure pulsed xenon lamp,the parameter design and distribution of the main-pre discharge circuit of the power supply are carried out,and suitable electrical parameters of the pulsed inductor are selected.Using ATP-EMTP simulation software,several discharge circuit faults with serious consequences of pulsed pump power are analyzed,and the extreme operation conditions of the protection inductor and the ballast inductor are determined.Taking the protection inductor with the highest parameter requirements among three types of pulsed inductors as an example,the pulsed inductor is designed.A design method of the solenoid type inductor was presentd based on temperature constraint.Based on this method,304 stainless steel was selected as the coil material for the 7 μH/48.6 mΩ protection inductor and the coil structure parameters were obtained.The finite element simulation model of the protection inductor is established,and it is found that the maximum stress of the solenoid type protection inductor is below the ultimate tensile strength of the materials.the simulation indicates that the protection inductor can still maintain the structure integrity and protect the shunt capacitor bank under the extreme condition.The solenoid type ballast inductor and the solenoid type preionization inductor can also be designed using this method.A optimal design method of the compact planar inductor was presentd based on the particle swarm optimization,which can be used to find the coil structure parameters that can minimize the coil volume.To establish the inductance constraint in the optimization,a more accurate numerical model of the planar inductor is established based on Bartky’s transformation method of elliptic integral calculation.The planar protection inductor was optimally designed by the planar inductor optimal design method.By the electromagnetic structure coupling simulation,it is found that the maximum electromagnetic stress appears on the innermost layer of the coil and the maximum stress of the planar protection inductor is below the ultimate tensile strength of the materials.So the designed planar protection inductor can meet the structural strength requirements of the protection inductor in the power supply.Finally,according to the actual needs of the pulsed pump power supply,the solenoid type pulsed inductor is more suitable and chosen in the power supply.The current injecting test of three pulse inductor samples and the discharge test of the power supply prototype were carried out.The test results show that the designed pulse inductor’s ability to withstand failure and adjust waveform meet the requirement of the pulsed pump power supply.