Development On Multi-functional Integrated Data Acquisition Platform Based On FPGA For Pulsed Magnets

The technology of pulsed high magnetic field is the only effective means to provide magnetic field above 50 T,which is of great significance in the field of modern scientific inquiry and industry.The pulsed magnets is the key experimental reference element for the magnetic field,whose insulation,discharge pulsed current are indispensable components of the pulsed magnetic field device.Accurate measurement of pulsed magnetic field,pulsed current and insulation is an essential component of the experiment.For the demand of pulsed high magnetic field device,the accurate acquisition of pulsed current plays a crucial role in high stability magnetic field control systems.Measuring the high magnetic field distribution and locating the maximum magnetic field is a key part of the pulsed magnetic field experiment.The traditional magnetic field measurement method using a hollow single coil based on Faraday's electromagnetic induction law requires repeated experiments to determine the magnetic field distribution,which greatly reduces the efficiency and accuracy of scientific experiments.In addition,when the pulsed magnets is used,because it needs to withstand a series of harsh conditions such as high voltage,high current,high temperature rise,the life is severely limited by the damage of the insulation condition,and the safe operation of the pulsed magnets will be affected by the gradual expansion of the fault range.In this regard,this paper will propose a integrated data acquisition platform scheme to measure the magnetic field distribution with multiple channels,to measure the pulsed current of high stable magnetic field with high precision,and to measure the weak,high frequency signal of the pulsed magnet insulation damage at high speed,which is used to determine whether the magnet insulation has failed.This paper will firstly design a data acquisition system based on FPGA for multichannel of magnetic field distribution,high precision of pulse current and high frequency of partial discharge signal.The AD7656,AD7760 and AD9226 are used as sampling modules to collect the induced voltage and magnet current signal of the detection coil.By improving the PCB circuit design and using large-capacity SDRAM as the memory,the high-precision,multi-channel and high-speed integrated targets of the ADC are realized,and a multi-function data acquisition system is developed.The experimental results show that the multi-channel acquisition module developed in this paper can meet the requirements of magnetic field configuration measurement,and the high-precision acquisition module can meet the high-speed and high-precision measurement requirements required for highprecision control of flat-top magnetic field/current waveform and high-speed measurement module can effectively detect pulsed magnet insulation damage signal.The multi-functional integrated acquisition system developed in this paper will lay the foundation for the application and research of pulsed magnetic field technology in the future.