A method for controlling an inverter including, when it is detected that a voltage across a bus capacitor, for example, a bus voltage, is excessively large, controlling a photo-voltaic (PV) battery to short-circuit so that the bus voltage drops. When the bus voltage drops to a particular value, continuing charging, by the PV battery, the bus capacitor to control the bus voltage to rise so that the bus voltage is kept within an operating voltage range of the inverter and the inverter can be equipped with a PV battery having a higher open circuit voltage. Therefore, a charging rate of the bus capacitor can be increased and a startup speed of the inverter can be increased.