Distribution network grounding protection device with double transformer configuration and its sampling control method

Abstract

The invention discloses a power distribution network grounding protection device with dual transformer configuration, comprising an FPGA main control module, an analog quantity sampling module with dual transformer configuration, an Ethernet module, an input-output module, and a human-computer interaction module , a power supply module; the FPGA main control module is respectively electrically connected with the analog sampling module, the Ethernet module, the I / O module, and the human-computer interaction module; the power supply module is respectively connected to the FPGA main control module, the analog sampling module, Ethernet module, input and output module, and human-computer interaction module provide the required working voltage. The invention can meet the measurement accuracy requirements of large signal and small signal, respectively corresponding to the conditions of low fault resistance and high fault resistance; the control method of threshold switching is used to select and switch the sampling signal values ​​of the two transformers, so as to realize the sampling Optimal selection of signals.

Description

technical field [0001] The invention relates to the technical field of distribution network relay protection, and more specifically, relates to a distribution network grounding protection device with a dual transformer configuration and a sampling control method thereof. Background technique [0002] The neutral point small resistance grounding system is widely used in the distribution network. Single-phase ground fault is one of the main types of distribution network faults. At present, the main protection configuration scheme is staged zero-sequence current protection, but its sensitivity is limited by the transition resistance. The impact of the fault is relatively large, and it cannot meet the requirements of single-phase high-impedance ground fault detection. In the current solution, in addition to using zero-sequence current, the sensitivity and accuracy of ground fault detection can also be improved by introducing zero-sequence voltage. At the same time, when a high-...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problem of low sampling accuracy common in current distribution network protection devices, the present invention provides a distribution network grounding protection device with a double transformer configuration. The measurement accuracy requirements of large signals under fault resistance, while meeting the measurement accuracy requirements of small signals under high fault resistance

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