Grid-connected and off-grid switching control method and device suitable for energy storage type UPS (Uninterrupted Power Supply) system

The invention discloses a grid-connected and off-grid switching control method and device. The method is applied to the energy storage type UPS system, the energy storage type UPS system comprises an energy storage converter, the energy storage converter is composed of a plurality of DC/AC modules, AC side outputs of the plurality of DC/AC modules are connected to a three-phase power grid through a phase-shifting transformer, and the method comprises the steps of obtaining related parameters before grid-connected and off-grid switching, and under the condition that a preset switching condition is met, switching from grid connection to grid disconnection is carried out. According to the grid-connected and off-grid switching control method suitable for the energy storage type UPS system provided by the invention, stable switching of grid-connected and off-grid dual modes can be realized, and current impact and load voltage abrupt change at the switching moment are avoided. 本申请公开了一种并离网切换控制方法以及装置。其中，所述方法应用于储能型UPS