question

bruce-kirk avatar image

Erratic VE.Bus DC Voltage and Current

Hello All

A client's system has this strange behaviour when battery voltage is low.

voltage-current-inconsistency.jpg

Battery BMS voltage and current are stable but VE.Bus voltage and current are up and down like a yoyo. These two graphs should be exactly the same if I'm not mistaken. In this period of about half an hour, I received about 200 VE.Bus Low Voltage problem and recovery emails from VRM Notifier. I watched the system in realtime yesterday and saw VE.Bus DC voltage spiking as high as 60V and as low as 41V in a space of a few minutes but BMS voltage was stable.

The system is single phase consisting of a Quattro 10kVA with 24kWh Blue Nova battery and a 10kWp PV array. Conditions have been cloudy for a few days so SOC is around 50%. The system runs on ESS.

Any help will be appreciated.

VE.Bus
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1 Answer
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wkirby answered ·

The very first logical explanation that springs to my mind is a poor connection somewhere on the battery cables between the battery and the Quattro.

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