PHASE-LOCKED LOOP, POWER CONVERSION DEVICE AND PHASE SYNCHRONIZATION METHOD

摘要

PROBLEM TO BE SOLVED: To improve a precision of phase synchronization in a phase-locked loop for single-phase AC.SOLUTION: The phase-locked loop is configured to further perform coordinate transformation on a voltage from an α-β coordinate system after quadrature coordinate transformation from three phases to two phases into a d-q coordinate system that is a rotation coordinate, and controls an ineffective voltage component into 0. As voltages Vα and Vβ in the α-β coordinate system, the phase-locked loop uses a real voltage of the single-phase AC subjected to phase synchronization as Vα and uses a value that is a time differentiation value of Vα and includes a frequency of the single-phase AC in a coefficient, as a pseudo voltage Vβ.SELECTED DRAWING: Figure 10