Block Diagram
The block diagram shows the structure of the signal fusion. The signal from the DC sensor (array of Hall sensors) is low pass filtered and the signal from the AC sensor (Rogowski coil) is high pass filtered. The transfer functions of the filters are chosen so that the output signal is proportional to the measured current.
Transfer Functions
The figure shows the magnitudes of the transfer functions of the sensors (blue), filters (orange), and the filtered sensor signals (yellow). When the transfer functions of the filters (yellow) are added with respect to phase, a signal proportional to the current is obtained.
To learn more about this type of signal fusion, see the patent “Method and electronic circuit assembly for combining output signals from electric systems having different signal frequency ranges” (WO2022200056A1).
Circuit and PCB design
The signal fusion is implemented using operational amplifiers. A current output has also been developed.
