September 6, 20232 yr Hey guys anyone else had this problem or suggestions on resolution... Seems to happen when the sun is showing off. Has happened twice now and I think it has to do with under recording of pv input and therefore incorrect disturbing, bus voltage has peaked at just over 400vdc.
September 6, 20232 yr Author There seems to be a correlation between high pv voltage and the high bus voltage... My panels seem to be hitting a voltage a bit higher than expected up to 118 and 120 volts. Mppt operating range is 60 - 115 but the voc is 145 volts. So to my mind the inverter should be able to deal with the over voltage and clip the solar accordingly. Any suggestions guys?
September 9, 20232 yr There seems to be a correlation between high pv voltage and the high bus voltage... My panels seem to be hitting a voltage a bit higher than expected up to 118 and 120 volts. Mppt operating range is 60 - 115 but the voc is 145 volts. So to my mind the inverter should be able to deal with the over voltage and clip the solar accordingly. Any suggestions guys? Afaik these inverters can clip excess amps, but can't do much about over voltage. How are your panels configured? 3S? If so you should think about changing to 2S. I operate my panels in 2S and the voltage is between 70-90V and works without issues.
September 9, 20232 yr Author Hi jumper, thanks for the reply. I've got 3s x2 but they are low voltage panels the max voltage without load is 119vdc. So with the inverter rated to 145vdc it should be able to deal with it to my mind. If I go with 2s x 3 I'll only just be around the 60volt underload and the mppt cuts in and out as a result....
September 9, 20232 yr Author I'm planning to change the config just to check... Will respond after to see if it affects the bus voltage..
September 10, 20232 yr I'm planning to change the config just to check... Will respond after to see if it affects the bus voltage.. If 3S is 120V then 2S should be around 80V, similar to mine which should work nicely. Give it a try with only 2 panels at first before rewiring them all.
September 10, 20232 yr Author Thanks for the advise. I've changed the config today but the weather is so bad it's difficult to see if everything works fine.. Underload I'm staying around 65volts, sowithin the range of the mppt 60-115v. Fingerscross it helps to lower the bus voltage on a sunny day...
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