Method for acquiring fundamental frequency component of phase-locked loop and phase-locked loop controller using the method

摘要

PURPOSE: A fundamental wave component acquiring method of a phase-locked loop control and a phase-locked loop control device using the same are provided to use a high-frequency pass filter, thereby preventing the reduction of phase angle detection speed generated by a low cut-off frequency. CONSTITUTION: Fixed-coordinate voltage is acquired by transforming system voltage into a two-phase fixed coordinate(S1000). The fixed-coordinate system voltage comprises a harmonic wave component in addition to a fundamental component. Rotating coordinate voltage is acquired by transforming the fixed-coordinate voltage into a two-phase rotating coordinate(S2000). The rotating coordinate voltage passes a high-frequency pass filter(S3000). Harmonic wave rotating coordinate voltage comprised of only the harmonic wave components is acquired by eliminating the fundamental component which is less than a cut-off frequency of the high-frequency pass filter(S4000). The fundamental component which is a direct-current component is acquired by subtracting the harmonic wave rotating coordinate voltage from the rotating coordinate voltage(S5000).