Analysis and design of an immunity test platform against D.C. and power-frequency magnetic field

Abstract

The magnetic field environment around tokamak devices is very strong, which affects the working characteristics of electrical and electronic devices. For the study of magnetic field interference problems and the qualification test of sensitive devices, an immunity test platform against both D.C. and power-frequency magnetic fields is designed in this paper, including the analysis and design of magnetic field generating coil and the power supply. The rated D.C. and power-frequency magnetic fields of the test coil are 200 mT and 50 mT, respectively, and the field inhomogeneity is 1.1. The electromagnetic design and the thermal design of the test coil are presented. The power supply adopts the three-stage series structure of rectifier, D.C. bus and H-bridge to enable the output of both D.C. and power-frequency currents. As the test requires a wide output current range with a high accuracy, an improved topology is proposed to ensure the stability and accuracy at all test levels. The operation principle and control strategy of the topology are analyzed and presented. The simulation results show that the topology and control strategy meet the design requirements.