| Due to the volume limitation and stability requirements of the device,the traditional way of voltage grade improvement has gradually shown more limitations.However,nowadays,the intelligent high-voltage generator has got rid of the main limitations due to the development of power electronics technology such as switch power supply technology,so that it has more portable and stable performance.High voltage generators are generally divided into ac high voltage generators,pulse high voltage generators and dc high voltage generators.Dc high voltage generator is widely used,which can be used as insulation strength test,leakage current test,high voltage equipment power supply,etc.Based on the analysis of the research process of this technology at home and abroad today,design a set of intelligent dc high voltage generator,use the method of the circuit principle analysis to identify the overall circuit of system parameters,and made a physical circuit module and its correct effectiveness has been proved by many debugging,finally combined into a complete circuit module circuit system,to complete intelligent control technology of pressure testing.The intellectualization in this design is to realize the dynamic control of the system frequency tracking and output ripple.Following the current relevant technical hot spots,several innovative schemes are proposed and designed to solve some technical difficulties.Good results are obtained through experiments and physical verification.In terms of technical innovation,this paper includes the following aspects: in the front end of the circuit system,switching power supply directly replaces EMI filtering circuit and rectification circuit to avoid high-frequency interference andsimplify the circuit;High frequency inverter is realized by using MOS tube with fault state feedback and active miller clamp to drive optocoupler chip and combining with DE inverter circuit.The output voltage is square wave of high frequency.Considering the core loss and winding loss of booster transformer,the core parameters and winding turns on both sides are determined by AP method,which improves the transmission efficiency.The voltage doubling rectifier is realized by using the new super fast recovery diode ES1 K.By combining STM32 and CPLD,the inverter frequency is tracked to realize ripple dynamic regulation and soft switch control.The flux gate probe combined with the peak difference demodulation circuit is designed independently to measure the output current with high precision.The output voltage is measured by using the resistance voltage divider circuit and combining with the instrument operational amplifier and isolated operational amplifier.Output current and voltage signals are collected by 16-bit dual-channel ADC to ensure measurement accuracy.The software algorithm can realize the dynamic regulation of voltage ripple in a certain range under different loads.The output voltage of this design is 2.4KV,the output current is 10 mA,and the ripple coefficient is less than 0.5%.The accuracy index of current measurement and voltage measurement is 0.1% and 0.5% respectively.In this paper,Comsol simulation software is used to conduct electromagnetic simulation of the probe independently designed,which proves the rationality of the fluxgate probe designed for current measurement. |
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