The Design Of Standard Strong Magnetic Field Source By Digital Control

With the development of scientific technology, the application of intermediate frequency strong magnetic field are used more and more widely, For instance testing in the induction heat treatment to medical tumor, high-frequency electrotome and induction heating, electromagnetic interference and scientific experiment and so on, But intermediate frequency standard strong magnetic testing is still a problem. Intermediate frequency standard strong magnetic field source viewed as intermediate frequency magnetic field testing equipment calibration foundation, is very important. Research in intermediate frequency standards and strong magnetic field sources is rare at home and abroad, leading to the lag behind intermediate frequency strong magnetic field detection equipment research and development. This topic is from the magnetic field project detection equipment research and development of national natural science foundation. According to the requirement of magnetic sensor and Instrument calibration, researching the intermediate frequency standard magnetic field numerical in control source, designing uniform standard stable alternating magnetic field.This paper analyzes the development situation and research of the intermediate frequency standards strong magnetic field source at home and abroad. According to the current need of the magnetic field frequency and the scope of strength, intermediate frequency standard strong magnetic field source contains intermediate frequency circuit and magnetic coil. Magnetic field generator circuit is mainly used in half-bridge converter topology structure, the connection mode of network. Inverter control part mainly use phase locked loop and peripheral control circuits, stable output waveform, and the current rules. Though need in the output of the magnetic flux density, design specifications of the Helmholtz coils. Getting through the magnetic field distribution of the most simple axisymmetric circle coils, analysis magnetic field of the Helmholtz coil, calculating the intensity of Helmholtz coil center axis of the magnetic field, the analysis of the theory has certain significance not only for this project, but also for subsequent research. Finally using Mathmatic and HFSS simulation software to analyze and simulate the magnetic induction strength of coil. evenness and homogeneity shape, and using magnetic field measuring instrument to test, then comparing the results, calculating error and analyzing error.This topic made some preliminary experiments on the source of strong magnetic field of the IF standard. Using Helmholtz coil tester of magnetic field to test, analyzing the theory and practical test error. to the homogeneous degree of the magnetic field coil and the shape of the homogeneity of simulation analysis, reach preliminary expected results. The results can explain that intermediate frequency standard strong magnetic field source can provided the basis of equipment accuracy in the existing many magnetic induction, And to the magnetic field sensors for calibration. In addition, the subject about the research of the magnetic field generated the space distribution stability, provides a better method for other magnetic induction equipment.