An apparatus and a method for protecting a grid connected inverter according to generating of grid under voltage

摘要

According to another aspect of the present invention, there is provided a protection device for a grid-connected inverter according to the generation of a system low voltage, comprising: a first output current sensing unit for sensing an output current of a grid- A first output current calculation unit for calculating the sensed output current by calculating a D axis and a Q axis current of the sensed output current; And determining whether a difference between the calculated output current and the reference current exceeds a predetermined range and if the difference between the calculated output current and the reference current exceeds the predetermined range, And a first output current control unit for reducing the output current.