Block Diagram
The block diagram shows the structure of the signal fusion. The signal of the dc sensor (array of Hall sensors) is low-pass filtered and the signal of the ac sensor (Rogowski coil) is high-pass filtered. The transfer functions of the filters are chosen in such a way 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). If the transfer functions of the filters (yellow) are added under consideration of the phase, a signal that is proportional to the current is received.
If you want to learn more about this type of signal fusion, please have a look at 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 with the use of operational amplifiers. Additionally, a current output was developed.
