Current mode not stable enough
Context
The converter makes noise while operating in current mode.
Description
The duty cycle of the power converter oscillates a lot in operation. This has been observed in open-loop and is independent of the control loop.
The harmonic content of the current measurements were studied for leg 1 on converter 2. This harmonic content shows some noise near the switching frequency and, more generally, a lot of noise on the current measurement.
Another potential problem is the fact that the measurement chain has a signal-to-noise ration that might be too small. The current measurement range is +/- 60A while the maximum expected current is +/- 8A.
Actions
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Document the noise on the current measure with the existing hardware -
Study a physical LC filter for the measurements -
Test the current mode with the filter and document the results for a single leg -
Brainstorm changes to the measurement chain in order to rise the signal-to-noise ratio and document them