Development Of Ground Current Measurement System In High Pulsed Magnetic Field Facility

In recent years, the high pulsed magnetic field has developed rapidly, which providesunprecedented experimental conditions for in-depth research of related scientific problems.And it also provides greater opportunities for new scientific discoveries and newbreakthroughs than ever. In order to ensure the normal running of the high pulsed magneticfield facility, it is necessary to detect the critical electrical parameters such as dischargevoltage, discharge current, magnetic intensity with high precision during the dischargeprocess. The negative terminal of the pulse power source is connected with the ground andthe grounding current is very small, when the system works well. But the grounding currentwill probably increase greatly and impacts the safety of equipment and people, when thesystem is out of work. Therefore it is desirable and significant to measure the groundcurrent.On the basis of analyzing the current measurement technology, this paper proposes touse the Rogowski coil and digital integrator design scheme to measure the groundingcurrent. In addition, according to the requirements of the detection system, application ofEthernet access technology based on fiber optic isolation can make the measurementsystem achieve relatively complete system functions of measurement and remotemonitoring including in situ measurements and data processing, remote control andmaintenance, fault alarm and information publishing and sharing.This paper introduces the design scheme of the hardware circuit and software design.The system uses TI32bit fixed-point digital signal processing chip TMS320F2812as thesignal acquisition and control of the core, and it uses the analog-digital conversion modulefor data acquisition; network transmission part focuses on the implementation of the TCP/IP protocol based on DSP; comparing various integral algorithms of the digital integral part,improved Al-Aloui integral algorithm proves to be the final choice. The error between theamplitude response of this algorithm and the theoretical curve is in the range of7×10-3withhigh precision. In this paper the data acquisition and control programs are written,including the main program of sampling, the integral algorithm procedure and the networkcommunication procedure. The experimental results indicate that the measurement system achieves the designgoal, which can meet the remote measurement and control of the ground current of the highmagnetic field facility.