Electric shock fault detection method based on leakage current instantaneous amplitude-phase product sum features

Abstract

The invention discloses an electric shock fault detection method based on leakage current instantaneous amplitude-phase product sum features, and the method organically combines discrete Hilbert transform with a break variable calculation method, and comprises the steps: firstly extracting the break features of the accumulated sum of leakage current instantaneous phase differences through employing the instantaneous phase of a power supply voltage as a reference standard vector; then, calculating the summed sums of the sudden increments of the instantaneous amplitudes of the total leakage current signals, and extracting the proportional characteristics of the abrupt change of the amplitudes of the adjacent periods of the sampling signals; finally, using the product and sudden change characteristics of the instantaneous phase and amplitude of the total leakage current signal transient process and the cumulative effect function of the technical instantaneous amplitude-phase characteristic information in the transient change process as the criterion of electric shock fault detection in the low-voltage power grid, and providing a new electric shock fault detection method. The technicalproblems of misoperation and low correct commissioning rate generally existing in a low-voltage current residual current protection device are solved.

Description

technical field [0001] The invention belongs to the technical field of grid fault detection and relates to an electric shock fault detection method based on the instantaneous amplitude-phase product sum characteristic of leakage current. Background technique [0002] Most of the currently operating residual current protection devices use the fixed action boundary setting value as the basis for the judgment and identification of electric shock faults, so there are misoperations and failure refusals. [1-2] . Although some scholars have done a lot of research and improvement on the hardware structure and leakage current detection of residual current protection devices [3-10] , has improved the technical performance of device to a certain extent, but still does not fundamentally solve the problem of its misoperation and correct commissioning rate low. How to identify the electric shock fault through the effective characterization index of the measurable total leakage current h...

AI Technical Summary

Problems solved by technology

[0005] In summary, the Hilbert transform and sudden change technology provide theoretical and technical feasibility for the application of the total leakage current in the electrical circuit for fault detection, but there is no weak realization of the residual current protection technology for low-voltage power grids. The instantaneous phase angle and instantaneous amplitude product and characteristic information of the non-stationary signal transient process are effectively extracted and related reports of fault detection are realized, which leads to certain limitations in practical applications

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