Strange THD Behavior with ADE9000 After Frequency Drop

Hi,

I’m using the ADE9000 to monitor the power grid, but I’m encountering a strange issue with the THD values. All other outputs from the ADE9000 are correct, but the THD behaves oddly.

I’m working with a 50Hz fundamental frequency.

When simulating in Omicron, the THD values appear accurate. However, when I simulate a frequency drop from 50Hz to 40Hz, the THD value jumps to 400%, which is expected for this scenario.

The problem arises when I return to 50Hz: sometimes the THD value recovers and goes back to normal, but other times it remains stuck at 400%, instead of reverting to the correct value.

Has anyone experienced this issue or have any ideas about what might be causing it?

Thanks in advance!