Method and device for controlling off-grid output voltage of energy storage inverter

The embodiment of the invention discloses a method and a device for controlling off-grid output voltage of an energy storage inverter. The control method for the off-grid output voltage of the energy storage inverter comprises the following steps: predicting and estimating a power grid voltage instantaneous value; on the basis of the power grid voltage instantaneous value and the real-time power grid voltage, grid-connected and off-grid changes of the energy storage inverter are determined; and according to the grid-connected and off-grid change of the energy storage inverter, adjusting a grid voltage adjustment coefficient to suppress the off-grid voltage abrupt change of the inverter. Therefore, according to the scheme, the grid-connected and off-grid change of the energy storage inverter can be actively monitored by predicting and estimating the instantaneous value of the grid voltage, and the grid voltage regulation coefficient is adjusted in time according to the grid-connected and off-grid change of the