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iicsys / pypmu

pyPMU - Python implementation of the IEEE C37.118 synchrophasor standard
BSD 3-Clause "New" or "Revised" License
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Frequency error #4

Open cepedajaime opened 6 years ago

cepedajaime commented 6 years ago

Hello, I am trying to use your Python app (pyPMU) in its pdc option. However, I have problems with reading the data from ints special format, mainly regarding the frequency. This variable is not correct. I am using PMU data in 60 Hz. In this connection, I already read the previous issue named "Trouble Reading from SEL735" and I did your suggested change in line 2144 in frame.py, after which it works. However, the frequency keeps in 60.06 Hz, almost constant (please see the attached figure).
freq_pypmu I realized that this value was also reported on the mentioned previous issue "Trouble Reading from SEL735". Therefore, please help me with suggestions for solving this inconsistency. Thanks in advance for your help and for sharing this so interesting application.

sstevan commented 6 years ago

Hello Jaime,

As already mentioned here: https://github.com/iicsys/pypmu/issues/3#issuecomment-356403846 we are unpacking FREQ field as the frequency deviation. Please check the image below: c37 118

So we do not expect to get there 60 as for nominal frequency. Nominal frequency is defined inside the Configuration Frame and theFREQ field should carry deviation.

So if you can provide FREQ as Actual Frequency - Nominal Frequency in mHz it will work.

Please let us know if you think this is misinterpreted. If you could share with us your sample data we might have a solution for you - how to adjust the script to get correct measurements.

However, there might be a bug in FREQ range validation that I have just noticed if you are trying to send actual frequency deviation in mHz which can be solved by editing line 2144 in frame.py.