A power voltage generating apparatus supplies a power voltage to a plurality of pixel circuits of a display apparatus. The power voltage generating apparatus includes: a high voltage converter to generate a high voltage; a low voltage converter to generate a low voltage; a switching circuit to alternately output the high voltage and the low voltage at a power voltage terminal as the power voltage; and a discharging unit coupled to the power voltage terminal and configured to discharge the power voltage terminal until a voltage output is converted from the high voltage to the low voltage by using the switching circuit.