Research And Experiment On Performance Of Energy Storage Capacitor In Soil Sterilization Pulse System

The prevention and control of verticillium wilt of cotton is a worldwide difficult problem.Many methods,such as crop rotation and chemical fumigation,have been used to control verticillium wilt of cotton,but the effect is not ideal.In consideration of the high efficiency of high voltage pulse current in sterilization and pest control,soil high voltage pulse sterilization technology was used to control cotton verticillium wilt,and the effects of treatment voltage,cycle number and electrode buried depth on verticillium wilt control were studied.The core component of the high voltage pulse system is the energy storage capacitor with charge and discharge function.In this paper,the single-phase Na Nb O₃（NN）and(Bi_0.5Na_0.5)Ti O₃（BNT）ceramic capacitors are modified respectively by ion doping and component recombination methods and their properties are studied and tested.The main contents are as follows:Firstly,Na(Nb_1-xTa_x)O₃capacitor was prepared by Ta ion doping at B position for single-phase NN ceramic capacitor,which improved the breakdown field strength and saturation polarization strength,laying a foundation for the preparation of composite ceramic capacitor.The(Bi_0.5Na_0.5)_0.925Sm_0.05(Zr_xSn_0.2-xTi_0.8)O₃（BNSZST）ceramic capacitors were prepared by introducing Sm ions at site A and Zr ions and Sn ions at site B.The results show that when x=0.08,the ceramic grain is the most dense,the effective energy storage density reaches 4.456 J/cm³,and the corresponding energy storage efficiency is 86.7%.In terms of temperature stability,the capacitor can keep stable energy storage performance in the range of 40-140℃under 240 k V/cm electric field.In addition,the ceramic capacitor ceramic has a power density of 22.11 MW/cm³and a current density of 442 A/cm².Subsequently,the properties of 2wt%Mn doped（1-x）Na Nb O₃-x(Bi_0.5Na_0.5)Ti O₃（NN-BNT-Mn）composite ceramic capacitor were prepared by composition-based composite method.The results show that when x=0.3,the density of the composite material reaches the best,and the comprehensive energy storage performance of the corresponding 0.7NN-0.3BNT-Mn ceramic capacitor is the best,in which the effective energy storage density is 2.464 J/cm³,and the energy storage efficiency is 85.8%.In addition,charge-discharge performance and temperature stability tests show that the ceramic capacitor has a power density of 18 MW/cm³and a current density of 361 A/cm²,and can maintain stable performance below100℃.In addition,（1-x）Na(Nb_0.95Ta_0.05)O₃-x(Bi_0.5Na_0.5)Ti O₃（NNT-BNT）composite ceramic capacitors are also studied.The results show that when the BNT content is 40%,the sintering effect is the best.The corresponding 0.6NN-0.4BNT ceramic capacitor has higher effective energy storage density（3.607j/cm³）,power density（19 MW/cm³）and current density（382 A/cm²）.And can keep stable performance in the range of 30-80℃.Finally,compare the preparation of ceramic capacitor energy storage performance,charge and discharge performance,and comparing temperature stability,select the most excellent comprehensive properties of BNSZST ceramic capacitor as the energy storage component,set up soil sterilization system,high voltage pulse on the vaccination of cotton verticillium wilt bacteria soil soil sterilization experiment,the experimental results show that the control effect of verticillium wilt on cotton could be improved by increasing discharge voltage,discharge times and electrode embedding depth.In each experimental group,when the treatment voltage was 1000 V,the number of cycles was 1000,and the electrode buried depth was 4.8 cm,the incidence of cotton seedling was 80%,the disease index was 35%,and the control effect was obvious compared with the control group.