A power control system includes a power regulator having a plurality of power PMOS transistors connected to a power source in parallel and configured to supply current and voltage controlled according to an input lamp voltage, a current sensing unit connected to the power source and configured to sense currents flowing through a plurality of target PMOS transistors located at predetermined positions among the PMOS transistors, a current mirror unit connected to a first regulated voltage terminal and configured to generate a plurality of currents equal to the sensed currents, a comparator unit configured to total the generated currents to convert the totaled currents into a voltage, and to generate a voltage difference between the voltage and a predetermined reference voltage, and a current bias circuit unit connected to a second regulated voltage terminal and configured to control a bias current according to the generated voltage difference.