Substation long cable residual current detection method, device, equipment and storage medium

Abstract

The invention relates to a method for detecting the residual current of a long cable in a substation, a device, computer equipment and a storage medium. The method includes the following steps: simultaneously detecting the effective value of the current and the effective value of the phase voltage at the beginning and end of the cable through a leakage detection unit; sending a data synchronization command to the leakage detection Unit, so that the leakage detection unit uploads the current effective value and phase voltage effective value corresponding to the cable head and end; according to the received current effective value and phase voltage effective value data, the actual effective value of the remaining current of the cable is calculated. The current effective value and the phase voltage effective value at the head and end of the cable are simultaneously detected by the leakage detection unit, and the actual effective value of the residual current of the cable is calculated according to the detected current effective value and phase voltage effective value data, so as to realize the high detection of low-voltage AC cables. The real-time monitoring of resistance grounding can monitor the insulation status of the AC power system in real time, effectively improve the status monitoring ability of the AC power system, and prevent electrical fire accidents in substations.

Description

technical field [0001] The invention relates to the field of low-voltage AC power supplies in substations, and more specifically refers to a method, device, equipment and storage medium for detecting residual current of long cables in substations. Background technique [0002] In recent years, relevant national standards, industry standards and regulations have gradually refined the requirements for power cables, control cables, and communication cables in substations to be divided into trenches and layered isolation. As of May 2019, the investigation of potential fire hazards in substation cables is as follows: [0003] 1. Ditch rectification: There are 39,238 substations in operation, and 440 substations have been carried out, accounting for 1.12%. [0004] 2. Layered rectification: 10,355 substations have completed layered isolation, accounting for 26.39%. [0005] State Grid Jibei, Jiangsu, Chongqing, and Fujian 4 companies selected 21 substations of 220kV and above wit...

AI Technical Summary

Problems solved by technology

[0007] In the existing scheme, when detecting the residual current and armored grounding current of long cables, since the current phase at the head and the end must be sampled synchronously, the calculation of the residual current requires the combined value of the head and the end. Since the length of the cable is several hundred meters, it is unlikely that the residual current The secondary output lines of the CT are combined and synthesized, and the first and last segments are sampled synchronously through the GPS (Global Positioning System), which requires too high precision for the time, and the actual execution error is relatively large

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