The invention belongs to the technical field of power
system synchronization, and particularly relates to a three-phase phase-locked
loop control method and device. The method comprises the following steps: acquiring a q-axis
power grid voltage sampling value of a three-phase
power grid voltage sampling value under a two-phase rotating coordinate
system; inputting the q-axis
power grid voltage sampling value into a complex coefficient filtering sliding mode observer, extracting
alternating current frequency multiplication disturbance brought by the distorted power
grid voltage, and obtaining a q-axis voltage estimated value, a
direct current estimated value in the
alternating current frequency multiplication disturbance and a total
alternating current estimated value in the alternating current frequency multiplication disturbance; the complex coefficient filtering sliding-mode observer is obtained by connecting a complex number filtering item of a complex coefficient filter in parallel in the sliding-mode observer; and calculating a
phase angle estimation value of the three-phase phase-locked loop after feedback compensation based on the q-axis voltage
estimation value, the
direct current quantity
estimation value in the alternating current frequency multiplication disturbance, the total alternating current quantity estimation value in the alternating current frequency multiplication disturbance and the power grid phase
voltage amplitude. The control efficiency and accuracy of the phase-locked loop are improved, and the method has good stability and robustness.