Power grid voltage frequency and phase angle detection method and system and single-phase power grid detection system

Abstract

The invention belongs to the technical fields of power grid performance testing devices and electrical fault detection devices, and discloses a power grid voltage frequency and phase angle detection method. The method comprises the steps that a single-phase power grid voltage signal is acquired, an integrator and a state observer are constructed, a power grid voltage signal and an orthogonal signal thereof are obtained and substituted into a phase-locked loop formula by serving as variables, and then frequency and phase angle information of a power grid is obtained. According to the method, key information such as the amplitude, the frequency and the phase angle of the power grid is measured by using a PLL; the dynamic response speed is high, and the excellent steady-state precision is achieved under the conditions of power grid frequency changes and harmonic interference; a QSG is designed from the angle of the observer, pole configuration is more flexible, poles can be configured ona left half plane arbitrarily, and the range that parameters can be adjusted is wider; and the dynamic response speed and the harmonic suppression capacity are high. When the method is used for measuring the power grid voltage, the better dynamic performance and the better harmonic suppression performance are achieved, the parameter configuration range is wider, and arbitrary configuration can beachieved on the left half plane.

Description

technical field [0001] The invention belongs to the technical field of electrical performance testing devices and electrical fault detection devices, and in particular relates to a grid voltage frequency and phase angle detection method and system, and a single-phase grid detection system. Background technique [0002] At present, the existing technology commonly used in the industry is as follows: in the single-phase power grid technology, it is often necessary to detect the amplitude, frequency and phase angle of the single-phase power grid voltage, and in the three-phase power grid, the signals of the dq axes can be obtained through clark transformation , and then controlled by the PLL. However, the single-phase power grid has only one phase, so it is necessary to use a fictitious quadrature signal to generate the QSG, and then obtain the corresponding power grid information through the PLL. Due to its simple structure and small amount of calculation, SOGI-PLL is one of ...

AI Technical Summary

Problems solved by technology

[0003] To sum up, the problems existing in the prior art are: after comprehensively considering the dynamic performance and steady-state performance, the adjustable parameters of SOGI-PLL are fixed at constant values, and under the conditions of frequency hopping and harmonic interference, the dynamic performance and suppression There is still room for improvement in the ability of harmonics

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