Hz is all over the place when I am on battery

Hz is all over the place when I am on battery

I have two Powerwall 2 units with SolarEdge Inverter. When the grid goes down and I am running on battery power, the HZ fluctuates from 60Hz to 71Hz in the 80s and I observed and videoed it exceeding 100 Hz.

Are there any settings that I should be looking at to get the Hz stable at 60Hz?

gregb | March 13, 2018

I have very little specific knowledge of Tesla Powerwalls or SolarEdge inverters, but it sounds to me like neither the Powerwalls or the SolarEdge are the "master". These devices are designed to synchronize to the electric grid, but in the off-grid case they are essentially referencing each other and "chasing their own tail" so-to-speak. The solution would be for one or the other (Powerwall or SolarEdge) to become the "master" and generate the reference 60 Hz. signal. If this is not possible, then another device could be added to provide the reference. This could be a small box that generates a low power (sub-Watt) 120 VAC, 60Hz. reference. Such a device would at its simplest, have a quartz crystal oscillator as the time reference.