Line protection control method and microcomputer protection device

Abstract

The embodiment of the invention provides a line protection control method and a microcomputer protection device. The method is applied to the microcomputer protection device. The method is used for controlling a circuit breaker in a power supply line. The power supply line comprises the circuit breaker and a plurality of distribution transformers, and the circuit breaker is located in a primary side line of the plurality of distribution transformers. The method in one embodiment comprises the following steps: monitoring the current of a power supply line under the condition that the circuit breaker is in a switching-on state; when it is detected that the current of the power supply line reaches a set quick-break protection constant value, judging whether the voltage on the power supply line meets a tripping protection condition or not; and when it is detected that the current of the power supply line reaches a set quick-break protection constant value and the voltage on the power supply line meets a tripping protection condition, determining that a line fault occurs in the power supply line, and sending a protection tripping instruction to the circuit breaker, so that the circuit breaker executes a tripping operation according to the protection tripping instruction. Therefore, both the power transmission success rate and the effective protection of the line can be considered.

Description

technical field [0001] The present application relates to the technical field of power transformation and distribution, in particular, to a line protection control method and a microcomputer protection device. Background technique [0002] In some power supply scenarios, for some early-built enterprise power supply stations, the circuit conditions of the power supply lines are complicated. One circuit breaker controls multiple power distribution transformers, and some circuit breakers control as many as 20 power distribution transformers. The capacity of each transformer is roughly 100-2000kVA, and the capacity of each transformer may be the same or different. The total capacity of the transformers on the power supply line where a circuit breaker is located is about 13MVA. [0003] The power supply line is 3 kilometers long, and many overhead lines are used, which are prone to line failures. In the event of a short-circuit fault, the feeder circuit breaker will perform pro...

AI Technical Summary

Problems solved by technology

Because there are a large number of feeder transformers on the power supply line, taking a circuit breaker connected to 20 transformers as an example, at the moment when the circuit breaker is switched on, the excitation inrush current generated by 20 transformers receiving power at the same time is large, and exceeds the fixed value of the quick-break protection, so it is related to the circuit breaker. The protection device associated with the transformer will draw a conclusion that the quick-break trip protection should be performed at this time according to the fact that the current has exceeded the fixed value of the quick-break protection, and control the circuit breaker to trip, which is also an important reason for the relay protection action of the transformer. A hidden danger that has not been fundamentally resolved for a long time

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