Online direct-current grounding monitoring system for power distribution automation terminal

Abstract

The invention discloses an online direct-current grounding monitoring system for a power distribution automation terminal. The system comprises a processor, a direct-current grounding monitor, an anode grounding warning signal output module, a cathode grounding warning signal output module and a power supply module. The processor is respectively connected with the direct-current grounding monitor, the anode grounding warning signal output module, the cathode grounding warning signal output module and the power supply module. The online direct-current grounding monitoring system for the power distribution automation terminal has advantages that a voltage acquisition unit acquires voltage to ground of positive and negative buses of a direct-current system in real time and transits to the processor; by control of on or off of a detection bridge relay, insulation resistance to ground of the positive and negative buses of the system can be calculated according to changes of voltage to ground of the positive and negative buses of the direct-current system, the insulation resistance of the system is compared with a warning threshold, and warning signals are output for warning, so that the problem of equipment maloperation caused by insulation decline can be effectively avoided to guarantee safety and reliability in operation of power distribution network equipment.

Description

technical field [0001] The invention relates to the technical field of distribution automation terminals, in particular to an online monitoring system for DC grounding of distribution automation terminals. Background technique [0002] With the full implementation of the distribution network automation project, the number of DTU / FTU put into operation is increasing day by day, and the outdoor distribution automation device puts forward higher requirements for the operating environment of the distribution network equipment. Due to the wide range of distribution network equipment points, the complex surrounding environment, and the humid air and abundant rainfall in coastal areas, outdoor electrical equipment often produces condensation, corrosion and other problems, resulting in a decrease in system insulation. A large number of distribution network automation equipment adopts electric operating mechanisms. Once the insulation of the equipment control circuit drops and DC gro...

AI Technical Summary

Problems solved by technology

Due to the wide range of distribution network equipment points, the complex surrounding environment, and the humid air and abundant rainfall in coastal areas, outdoor electrical equipment often produces problems such as condensation and corrosion, which cause system insulation to decline

A large number of distribution network automation equipment adopts electric operating mechanisms. Once the insulation of the equipment control circuit drops and DC grounding occurs, it will easily lead to misoperation of the equipment and endanger the safety of grid equipment and personal safety.

[0003] For example, in February of this year, the DC system of an automated ring main unit in an urban area caused the positive pole to be grounded due to a module failure. At the same time, the 5# contact switch closing control circuit decreased the ground insulation due to condensation, which eventually caused the contact switch to close by mistake, causing Two 10kV lines run in closed loop, which creates a great potential safety hazard

In order to solve such problems, the environment inside the cabinet is dehumidified and blocked, but no obvious effect can be achieved. In addition, the equipment has its own defects, and there are still operational risks when a DC ground fault occurs.

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