Analysis and test of a 1m / 275 mT large-scale high-intensity magnetic field immunity test coil system for ITER

Abstract

The magnetic field immunity test is a qualification procedure for all types of electrical and electronic equipment located in ITER Tokamak areas where the static magnetic induction is higher than 5 mT. To perform the magnetic field immunity tests, a large-scale high-intensity magnetic field coil system required by ITER organization was developed and tested. The designed test coil system is capable of generating a homogeneous magnetic field with a maximum magnetic flux density of 275 mT in a cubic test zone with a side-length of 1 m. Since the scale and intensity of the test field are high, it is important to ensure the stability of the test coil system. In this paper, we report the engineering analysis and test results of the ITER test coil system. First, the water cooling analysis and design based on the finite element method (FEM) were performed to ensure the thermal stability. Then, the equivalent stress and deformation of the coil system under rated condition and seismic event were analyzed to verify the structural stability. Further, the inductance frequency characteristic of the coil system was analyzed through partial element equivalent circuit (PEEC) method to support the control strategy design of the power supply. In addition, a speeding-up inductance matrix calculation method was brought forward, which avoids redundant computation and significantly improves computational efficiency. At last, resistance, inductance, and temperature rise tests were completed to verify the design of the test coil.