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
- 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