Phase-locked loop, phase locking method and phase locking equipment

Abstract

The invention discloses a phase-locked loop, a phase locking method and phase locking equipment. The phase-locked loop comprises a frequency divider, a feed-forward frequency discriminator, a phase discriminator, a loop filter, a pulse adder-subtractor and a variable modulus frequency divider. In the working process of the phase-locked loop, the feed-forward frequency discriminator carries out frequency discrimination on an input signal, the change of the input frequency is rapidly detected, the output is changed through the feed-forward path, and the frequency division coefficient of the variable-mode frequency divider is adjusted, so that rapid frequency modulation is realized, and the phase-locked speed is improved. The phase discriminator carries out phase discrimination on the input signal, and the frequency division coefficient of the variable-mode frequency divider is adjusted by changing the output through the loop filter with a proportional-integral adjustment effect, so that accurate phase modulation is realized, the phase error of the output signal is eliminated, and interference such as quantization error can be effectively suppressed. Therefore, the technical problems that an existing phase-locked loop is low in phase-locking speed and narrow in phase-locking range, and static errors exist in phase output are solved.

Description

technical field [0001] The present application relates to the technical field of power harmonic measurement and detection, in particular to a phase-locked loop, a phase-locking method and a phase-locking device. Background technique [0002] In systems such as controllable AC-DC converters, static var compensators, active power filters, uninterruptible power supplies, and high-voltage DC The basis for power calculations and transformations between various reference coordinates. Power quality disturbances in the power system such as the existence of harmonics, notches caused by rectifiers using grid commutation, disturbances caused by instantaneous switching of capacitors, phase jumps and frequency fluctuations caused by grid voltage sags, and three-phase voltage imbalances in the grid And other factors will affect the accuracy of fundamental signal frequency and phase measurement. [0003] Phase-locked loop is the most commonly used phase synchronization method at present....

AI Technical Summary

Problems solved by technology

[0004] This application provides a phase-locked loop, a phase-locked method and a phase-locked device, which are used to solve the technical problems of the existing phase-locked loop with slow phase-locking speed, narrow phase-locking range, and static error in phase output

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