Magneto-optical current sensing for applications in integrated power electronics modules

摘要

We investigated the potential of using rare-earth ion Garnets, a type of magneto-optical (M-O) material, to sense magnetic field and thus currents in integrated power electronics modules (IPEMs). Firstly, we characterized the M-O materials by determining their Verdet constants, absorption coefficients, and M-O figure-of-merits (FOMs). Then dc and ac current sensing setups were specially designed and built and the characterized M-O materials were attached into a power module to sense the local magnetic field. The best location for the M-O materials was found by finite element modeling (FEM) of electromagnetic field distribution in the module. The dc current sensing results match well with both direct measurements and FEM results. In the ac current sensing, some issues on electromagnetic interference (EMI) were discussed and the sensing speed is tested up to 100 kHz. Finally, we provided miniaturizing designs for future integration and packaging of the M-O current sensors in IPEMs. (C) 2003 Elsevier B.V. All rights reserved. [References: 22]