Second-order generalized integrator structure based on frequency locking loop and phase-locked loop synchronization method

Abstract

The invention provides a second-order generalized integrator structure based on a frequency locking loop and a phase-locked loop synchronization method. The structure comprises a second-order generalized integrator, a frequency locking loop based on the second-order generalized integrator and a feedback loop; the second-order generalized integrator is used for receiving a voltage input signal of asingle-phase power grid and outputting a first orthogonal output signal and a second orthogonal output signal, wherein the voltage input signal comprises an input voltage signal and input frequency;the frequency locking loop based on the second-order generalized integrator is used for obtaining adjustment frequency and a third orthogonal output signal and a fourth orthogonal output signal according to the first orthogonal output signal; and the feedback loop is used for feeding back the adjustment frequency to the second-order generalized integrator to serve as new input frequency. The second-order generalized integrator structure based on the frequency locking loop provided by the invention improves the filtering ability of the DC components in the voltage signal, meanwhile improves the phase locking accuracy when the input signal contains the DC components and has better harmonic filtering ability.

Description

technical field [0001] The present invention relates to the technical field of communication, and more specifically, relates to a second-order generalized integrator structure based on a frequency-locked loop and a phase-locked loop synchronization method. Background technique [0002] In order to ensure the safe and stable operation of grid-connected single-phase power electronic devices, single-phase grid synchronization technology has become a very important control technology, and phase-locked loop is a simple and effective synchronization tool. A single-phase phase-locked loop usually consists of three parts: a phase detector, a loop filter, and a voltage-controlled oscillator. [0003] From a phase detector perspective, multiplicative phase detectors have a long history, but they still produce large double frequency components in their steady-state output. Therefore, the technology of generating the fundamental wave and its quadrature signal before the phase detector ...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the problem in the prior art that the phase-locked loop based on the second-order generalized integrator needs to retain the PI link, which makes the frequency-locked loop of the circuit too complicated, a second-order generalized integrator structure and phase-locked loop based on the frequency-locked loop are provided synchronization method

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