Protection starting judgment method and device based on Hankel matrix singular value decomposition

Abstract

The invention discloses a protection starting judgment method and device based on Hankel matrix singular value decomposition. The method comprises the following steps: collecting a current instantaneous value in a line during normal operation, forming a signal sequence, and setting a threshold value needed by protection starting judgment; when whether protection is started needs to be judged, extracting the signal components of current signals in a rolling mode; and when the absolute value of the element in the signal component is larger than a threshold value, judging that a fault occurs, andstarting protection. According to the invention, whether a fault occurs can be timely and effectively determined, the delay of fault detection is reduced, and the fault of the line can be rapidly andaccurately identified.

Description

technical field [0001] The invention belongs to the field of relay protection of electric power systems, and in particular relates to a method and device for judging protection startup based on Hankel matrix singular value decomposition. Background technique [0002] The access of distributed generators (Distributed Generator, DG) to the distribution network changes the power supply structure of the distribution network, affects the power flow distribution of the distribution network, and affects the sensitivity and selectivity of the traditional three-stage current protection. In distribution network protection, the detection of fault time is of great significance for judging whether the protection device operates. The current fault start judgment methods are mainly summarized as the fault start judgment method based on negative sequence current and zero sequence current, and the fault start judgment method based on electrical mutation The start-up judgment method, the faul...

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Problems solved by technology

[0003] The fault starting judgment method based on sudden change has a delay in the detection of the fault moment, and when a fault occurs at the moment when the current crosses zero, the detection delay will increase; the fault starting judgment method based on wavelet transform has edge effects and phase shifts, which will Affects the accuracy of the detection results, and is not suitable for scenarios that require high detection accuracy at the fault time. From this we can see that it is necessary to explore a new fault start judgment method

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