Alternating current phase frequency amplitude tracking and reconstruction method

Abstract

The invention discloses an alternating current phase frequency amplitude tracking and reconstruction method. According to the reconstruction method, alternating current frequency, phase and phase sequence relation of the acquired alternating current actual values are analyzed, then real-time estimation amplitude of each phase is obtained by utilizing a second-order generalized integrator and frequency and phase information, and then estimation amplitude is substituted into the proposed algorithm so as to reduce estimation frequency and phase error. According to the realized alternating current phase frequency amplitude tracking and reconstruction method, feedforward reference angle frequency does not need to be provided, alternating current phase, frequency and amplitude of any unknown angle frequency can be effectively analyzed, single-phase or three-phase voltage and current signals can be analyzed, and effective and rapid real-time reconstruction can be realized.

Description

technical field [0001] The invention belongs to the technical field of alternating current phase detection and reconstruction, and more specifically relates to a method for tracking and reconstructing alternating current phase, frequency and amplitude. Background technique [0002] With the rapid development of grid-connected power generation of new energy sources such as photovoltaics and wind power, distributed power generation has become a hot research object. The software phase-locked loop is a key technology in the distributed generation system, which is used to detect the frequency and phase of the polluted grid voltage and provide support for grid-connected power generation. The polluted power grid not only has unbalanced voltage, but also contains multiple harmonic components. It has been studied by more and more scholars, and many control and design schemes of phase-locked loops have been proposed. For example, a phase-locked loop based on low-pass filtering, a ph...

AI Technical Summary

Problems solved by technology

They all have the following problems: the precision of phase-locking is not high, the response is slow, and they are sensitive to system frequency changes and three-phase voltage unbalance

However, on the one hand, the above PLL technologies all need to provide the fundamental frequency of the measured object and the phase sequence of the three-phase voltage; on the other hand, when the AC harmonic component is large, the actual phase curve is not a standard sinusoidal curve, The angular frequency is not a constant value, but the angular frequency obtained by the above algorithm is a constant value, so the phase error will become larger. In complex applications such as frequency conversion speed regulation, unknown power grid, and phase-locked loop phase tracking, the above algorithm does not does not actually solve the problem

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