A power conversion apparatus having a rectifying unit configured to rectify single-phase power externally inputted and a power factor correcting unit configured to correct a power factor of the power rectified by the rectifying unit, the power conversion apparatus comprising: a control signal generating unit configured to detect the single-phase power inputted and generate a pulse signal controlling a rectifying operation of the rectifying unit, wherein the rectifying unit comprises a silicon-controlled rectifier thyristor, and wherein the control signal generating unit comprises: a signal detector configured to detect a line voltage of the single-phase power; a single-phase PLL configured to detect first and second zero-crossing points based on the line voltage of the single-phase power detected by the signal detector and generate a carrier signal based on the detected first and second zero-crossing points; and a PWM generator configured to compare a reference signal with the carrier signal generated and generate the pulse signal, wherein the reference signal decreases as time elapses, wherein the first zero-crossing point represents a zero-crossing point where the line voltage of the single-phase power is changed from positive to negative, and the second zero-crossing point represents a zero-crossing point where the line voltage of the single-phase power is changed from negative to positive, wherein the carrier signal comprises a first carrier signal and a second carrier signal, wherein the first carrier signal is generated when the first zero-crossing point is detected and is reset when the second zero-crossing point is detected, and the second carrier signal is generated when the second zero-crossing point is detected and is reset when the first zero-crossing point is detected, wherein the first and second carrier signals generated increase as time elapses, and wherein a width of the pulse signal generated by the PWM generator increases as time elapses. a control signal generating unit configured to detect the single-phase power inputted and generate a pulse signal controlling a rectifying operation of the rectifying unit, wherein the rectifying unit comprises a silicon-controlled rectifier thyristor, and wherein the control signal generating unit comprises: a signal detector configured to detect a line voltage of the single-phase power; a single-phase PLL configured to detect first and second zero-crossing points based on the line voltage of the single-phase power detected by the signal detector and generate a carrier signal based on the detected first and second zero-crossing points; and a PWM generator configured to compare a reference signal with the carrier signal generated and generate the pulse signal, wherein the reference signal decreases as time elapses, a signal detector configured to detect a line voltage of the single-phase power; a single-phase PLL configured to detect first and second zero-crossing points based on the line voltage of the single-phase power detected by the signal detector and generate a carrier signal based on the detected first and second zero-crossing points; and a PWM generator configured to compare a reference signal with the carrier signal generated and generate the pulse signal, wherein the reference signal decreases as time elapses, wherein the first zero-crossing point represents a zero-crossing point where the line voltage of the single-phase power is changed from positive to negative, and the second zero-crossing point represents a zero-crossing point where the line voltage of the single-phase power is changed from negative to positive, wherein the carrier signal comprises a first carrier signal and a second carrier signal, wherein the first carrier signal is generated when the first zero-crossing point is detected and is reset when the second zero-crossing point is detected, and the second carrier signal is generated when the second zero-crossing point is detected and is reset when the first zero-crossing point is detected, wherein the first and second carrier signals generated increase as time elapses, and wherein a width of the pulse signal generated by the PWM generator increases as time elapses.