VOLTAGE CONTROL APPARATUS AND VOLTAGE COTROL METHOD

A voltage control apparatus, when a voltage drop of an output voltage of an inverter is equal to or larger than a threshold, calculates first virtual impedance using various variables, calculates, such that an output current of the inverter does not exceed a rated value, second virtual impedance to be temporarily added to the first virtual impedance, calculates a virtual active voltage and a virtual reactive voltage by multiplying each of an active current and a reactive current calculated by the output current, by virtual impedance obtained by adding up the first virtual impedance and the second virtual impedance, and performs voltage control based on the virtual active voltage and the virtual reactive voltage such that each of the active current and the reactive current can approach each of an active current command value and a reactive current command value required of a power grid.