I've previously posted about our dual hybrid inverters jacking up the local voltage as they vie for the right to export to our G99 limit of 3.68kW. The only way I can start a charge on the EV while the inverters are exporting is to set "Inverter Max Output Active Power Percent" down on both inverters to a value that reduces export to zero. That stops the Zappi from going into overvoltage trip and enables it to enter "waiting for surplus mode" at which point, I can slowly increment "Inverter Max Output Active Power Percent" on each inverter in turn until they are both at 100% again. (Note that if the EV is plugged in from the morning in Eco+ mode, this isn't an issue, it's just when we get home on a sunny afternoon and try to get the EV charge going).
IMO, it would be useful if there was an option on dual inverter installations to reduce the ramp up rate for export so that there was opportunity for EV charger and other appliance automations to divert surplus before overvoltage occurs. This could be designed in (as a user-switched option?) to severely reduce inverter voltage increase in the range above 248V (for example), note but only when exporting.
In the meantime @Britkat has kindly exposed the "Inverter Max Output Active Power Percent" register via GivTCP but a command to set the register (GivEnergy/control/INVSerialNO/setActivePowerRate) is not acted upon by the inverter. I understand @Britkat has asked for help from the Givenergy devs to resolve this and anything that @TheDragon (GivEnergy) can do to expedite their response would be much appreciated. I'd like to use GivTCP with this control to "throttle" the inverter output in the hope that it will prevent overvoltage conditions.
Other than vying for the right to export during very sunny conditions, our dual hybrid inverters play very nicely together. If anyone else has any suggestions on how to cap dual inverter output voltage during export, I'd be glad to hear. I'll also post this text as an enhancement suggestion.
