Posco Energy Co., Ltd.

Posco Energy., Ltd.

Korea Fuel Cell Co., Ltd.

Jin Su Lee

Jeong Heum Lee

Sang Ho Moon

Jae Sig Kim

Ju Young Chang

An apparatus for protecting a grid-connected inverter from a low grid voltage includes a first output current sensor configured to sense an output current of a grid-connected inverter, a first output current calculator configured to calculate a D-axis current and a Q-axis current of the output current to obtain the output current that is sensed, and a first output current controller configured to determine whether a difference between the output current and a reference current exceeds a predetermined range, and to decrease the output current by a predetermined value when the difference between the output current and the reference current exceeds the predetermined range.

Apparatus and method for protecting grid-connected inverter from occurrence of low grid voltage

An apparatus for controlling overcurrent of a grid-connected inverter due to an abnormal grid voltage includes a grid voltage sensor configured to sense a grid voltage according to an output current of the grid-connected inverter, a voltage variation calculator configured to calculate a D-axis voltage and a Q-axis voltage of the grid voltage to obtain variation values of the D-axis voltage and the Q-axis voltage, and an output current controller configured to determine whether at least one of the D-axis voltage variation value and the Q-axis voltage variation value exceeds a set value of the grid voltage variation, and decrease the output current by a predetermined value when one of the D-axis voltage variation value and the Q-axis voltage variation value exceeds the set value of the grid voltage variation.

Apparatus and method for controlling overcurrent of grid-connected inverter due to abnormal grid voltage

Growing community of inventors

Pohang-si, South Korea

Jin Su Lee