Electromagnetic compatibility analysis and design of ITER Poloidal Field converter unit

Due to the space limitation and safety concerns, the non-same-phase anti-parallel connection structure is applied in the ITER Poloidal Field (PF) converter unit. Consequently, the electromagnetic interference (EMI) has been one of the main concerns in its design. And this paper mainly presents the electromagnetic compatibility (EMC) analysis and design for ITER PF converter unit. At first, an isolated phase bus is designed for the shielding of the alternating magnetic field generated by the a.c. busbars. Its shielding effectiveness has been verified by the analysis and experimental test. Then, the stray magnetic field, which is generated by the converter bridges and very hard to be shielded, is analyzed and measured. And the results will provide useful inputs for the EMC design and test of the instrument and control (I&C) system. At last, a large coil pair, able to generate a uniform static magnetic field with high strength, is designed to evaluate the effects on electronic devices and to demonstrate the reliable and safe operation of the converters under strong stray magnetic field.