Power grid grounding fault judging device

Abstract

The invention relates to the field of power supply monitoring devices, and especially relates to a power grid grounding fault judging device. The power grid grounding fault judging device prevents misoperation by adopting technologies such as using a leakage current to control actions, improving sampling sensitivity, adopting electromagnetic shielding, and setting a threshold to obstruct interference. The power grid grounding fault judging device is provided with a special power supply circuit and an overvoltage protection circuit for improving adaptive capability of the judging device; and two optional functions of alarm and action are set for facilitating electricity utilization customers. The power grid grounding fault judging device is mainly cooperated with a general monitor, is applied to a neutral point ungrounded system, and can be applied to a grounding system independently for judging grounding fault positions. Main electronic circuits such as a special power supply, an overvoltage protection circuit, a sampling device, an alarm device, an action device, and D1, D2, D3 backflow isolation devices are arranged in a special shell and packaged into a leak current sampling module 3DCsquare by using a special glue to form an element which is reliable and durable, and the element can be used for forming various kinds of grounding fault judging devices.

Description

1. Technical field [0001] The invention relates to the field of electric power supply monitoring devices, in particular to a grid grounding fault determiner. 2. Background technology [0002] Through long-term and extensive investigation and research, we have learned that although urban and rural power grids have been transformed, huge sums of money have been invested, and a lot of work has been done, the low-voltage distribution network suffers from large power loss, many power-related accidents, low-quality power supply, and difficult to manage the power grid. , Leakage protection failure and other long-standing problems have not been fundamentally resolved. After investigation and research, it is found that the grounding of the power supply system (including the artificial grounding of the neutral point and the ground fault of the power supply system) is the root cause of the above problems. Therefore, in addition to making people have a clear and correct understanding of...

AI Technical Summary

Problems solved by technology

In addition, due to the grounding of the neutral point of the power grid, electromagnetic interference, power switching surges and other reasons, the neutral point of the power supply is shifted instantaneously, which may cause misoperation, aggravate frequent movement, and seriously affect the normal power consumption. Users are impatient. So the leakage protector was artificially released and failed.

[0005] 2. Leakage protector overvoltage damage

Due to the poor anti-overvoltage ability of the leakage protector, and its circuit is directly connected to the low-voltage power supply system, and because the neutral point of the low-voltage power grid is grounded, lightning is introduced into the power grid, and due to ground faults, gate operation, system fluctuations, etc. The cause causes instantaneous overvoltage, which will cause overvoltage damage to the circuit board of the leakage protector and fail

[0006] 3. Leakage current shunt according to action

However, there are still problems such as misoperation and damage of sub-monitors that have not been completely resolved.

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