Transformer substation/power plant secondary circuit direct-current ground indicator and application thereof

Abstract

The invention provides a transformer substation / power plant secondary circuit direct-current ground indicator and application thereof. The indicator comprises a leakage current detection module, a signal processing module, an acousto-optic alarm module, an alarm threshold setting module and a power supply module; the leakage current detection module is a zigzag coil and is used for detecting leakage current passing through the direct-current circuit of the coil; the leakage current is analyzed and calculated by the signal processing module and compared with the set leakage current alarm threshold; if the leakage current continuously exceeds the set threshold for multiple times, the acousto-optic alarm module is started to perform acoustic prompt and signal lamp flashing arm; and when the acousto-optic alarm module is connected with an external communication circuit, the leakage current value and the alarm signals are transmitted to receiving equipment. The indicator integrated leakagecurrent sensing, signal processing, alarm and working power supply, can monitor the leakage current of direct-current electric equipment or direct-current electric circuits in real time, provides indication for accurately searching a direct-current grounded point, and is convenient for operation and maintenance personnel to timely and accurately process insulated destructive faults of a direct-current system.

Description

technical field [0001] The invention belongs to the technical field of electrical fault detection for relay protection and automation of electric power systems, and in particular relates to a secondary circuit installed in a substation / power plant, which can perform insulation monitoring on DC power consumption equipment or power consumption circuits and can perform ground fault alarms positioning device. technical background [0002] The substation DC power supply is an important part of the substation protection and automation system, and its safety is directly related to the normal monitoring of the power grid and the normal implementation of accident handling methods. The DC power supply systems of power plants, substations, and large-scale factories and mines use secondary DC power supplies with battery energy storage, which provide working power to signal circuits, control systems, relay protection, and automatic devices. The DC system is powered by 110V or 220V pow...

AI Technical Summary

Problems solved by technology

Regardless of the principle, the insulation monitoring device is currently only installed on the DC power supply panel, and it is only for detecting and judging that a certain DC main circuit is grounded, but cannot detect multiple electrical equipment and multiple power supply branches connected under the power supply branch. The specific grounding point of the circuit

Therefore, even if it is known that a feed-out branch on the DC power feed screen has DC grounding, the grounding equipment and grounding location cannot be clearly identified, which will also make it time-consuming and laborious to find the faulty grounding point and insulation drop point, and may lead to the use of disconnection The method of opening electrical equipment to find fault points will seriously affect the continuous operation of relay protection or automatic devices and pose a threat to system security. Positioning alarm device for DC ground detection and insulation monitoring of electric circuit

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