Microcomputer direct current monitoring device

Abstract

The invention discloses a direct current monitoring device of a microcomputer. The device is provided with an earthed monitoring circuit, a branch earthed measuring circuit and a microcomputer control circuit; the earthed monitoring circuit is connected with a positive bus and a negative bus of a direct current system through a positive terminal and a negative terminal; the branch earthed measuring circuit is connected with each branch circuit of the direct current system through a caliper or a branch sensor; and the earthed monitoring circuit and the branch earthed measuring circuit are connected with the microcomputer control circuit. The device is designed aiming at safe operation of direct current power, can monitor the situations of earthing, overvoltage and undervoltage of the direct current power and alarm, and can carry out online point fixing on the position of the earthed branch circuit, thereby ensuring safe operation of electric net control equipment. In the direct currentsystem with large distributed capacitance, the device can accurately judge the earthed branch circuit. When the branch circuit is earthed, online monitoring can accurately report the number of an earthed branch circuit without pulling the circuit and cutting off power, thereby avoiding inaction of a circuit breaker caused by circuit pulling and power interruption.

Description

Technical field: [0001] The invention belongs to the field of electric safety equipment, in particular to a microcomputer direct current monitoring device. Background technique: [0002] The DC system of power plants and substations is an operating system in which batteries and floating charging devices are connected in parallel to supply DC loads. power supply. [0003] Under normal circumstances, both positive and negative are insulated from the ground. When one point in the system is grounded, it generally does not affect the operation of the DC system, but when two or more points are grounded, it will cause a short circuit between the positive and negative poles. Misoperation and refusal of switches and protection circuits. At the same time, the failure of the DC system may cause greater failure hazards. Therefore, it is very important to use good instruments and accurate judgment methods when grounding occurs. [0004] From the composition of the grounding of the ac...

AI Technical Summary

Problems solved by technology

Similarly, when points A and C in the figure are grounded at the same time, and points A and D in the figure are grounded at the same time, it may cause the circuit breaker to trip.

[0007] (2) The hazards of negative grounding

Generally, it is designed and produced based on the three principles of "signal injection method", "Hall sensor monitoring method" and "magnetic saturation monitoring method". However, due to its low measurement accuracy, high false alarm rate, and poor anti-interference ability, especially When the distributed capacitance on the branch is very large, it cannot work normally at all

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