Patent ID: 8837186

Claim:
A power conversion apparatus comprising: a rectifying unit comprising a silicon-controlled rectifier thyristor (SCR) for rectifying externally input single-phase power; a power factor correcting unit configured to correct a power factor of the rectified power; a signal detector configured to detect the single-phase power; a single-phase PLL configured to detect first and second zero-crossing points based on the detected single-phase power and to generate a carrier signal that increases as time elapses based on the detected first and second zero-crossing points; and a PWM generator configured to compare a reference signal with the generated carrier signal and to generate a pulse signal having a width that increases as time elapses, wherein the rectifying unit rectifies the single-phase power by using the generated pulse signal input to a gate terminal of the SCR, wherein the single-phase PLL detects the first zero-crossing point where the single-phase power changes from positive to negative and detects the second zero-crossing point where the single-phase power changes from negative to positive, and wherein the single-phase PLL generates the carrier signal by: generating a first carrier signal when the first zero-crossing point is detected and resetting the first carrier signal when the second zero-crossing point is detected; and generating a second carrier signal when the second zero-crossing point is detected and resetting the second carrier signal when the first zero-crossing point is detected.