According to an embodiment, a method of controlling an inverter including a rectification unit rectifying inputted AC power to DC power, a smoothing unit smoothing the DC power, and a power conversion unit received the DC power from the smoothing unit to convert the received DC power into AC power having a predetermined size and frequency, the method includes receiving an abnormal signal of the inverter or an electric motor for driving the inverter, determining whether a DC terminal voltage of the smoothing unit is equal to or greater than a low voltage failure level when the abnormal signal is received, determining whether the power conversion unit is operating, and blocking current output of the power conversion unit when the DC terminal voltage is equal to or greater than the low voltage failure level and the power conversion unit is operating.