Multi-functional field sensing in IPEMs

In prior years, GMR-based, high bandwidth current sensing methods suitable for IPEM integration were developed. The methods were based on utilizing the deterministic geometry in the advanced packaging of CPES IPEMs and the low cost, high bandwidth GMR field detector technology. These methods were extended in Year 9 to include multi-detector methods, which allow superimposed field components to be easily separated using an inexpensive array of GMR detectors embedded in the IPEMs.

Figure 1 shows an experimental set-up using three field detectors with a three-conductor geometry whereby each conductor contains a different current waveform. The field detectors were used to make current measurements without using the traditional magnetic shielding to passively separate the individual fields. The oscillogram in Fig. 2 shows the resulting decoupled signals.

This methodology achieves multi-functional sensing in suitably designed IPEMs, enabling multiple critical signals to be extracted in addition to traditional device and gate currents (i.e., temperature, temperature gradients, IMMD rotor PM pole position, etc.). The integration of all of these features would not have been addressed but for the integrated approach used in the multi-physics CPES approach to IPEM development.