Rapid electrical fireproof current-limiting protection device

Abstract

The invention discloses a rapid electrical fireproof current-limiting protection device which comprises a zero-cross detection module, a change rate normalization module, a microprocessor, a current sensor, a main control switch and a load circuit. According to the device, the load current is normalized, so that the value of the relative change rate drt of the real-time normalized current on which the microprocessor performs short-circuit judgment is always kept between 0 and 1, and the threshold table is the same no matter what value of the rated current of the load is, namely, when the rated current of the load is the value of 10A or 32A or 63A and the like, the value of the relative change rate drti of the standard normalized current is the same, and the value of the relative change rate drti of the standard normalized current is the same. Different current-limiting protection devices do not need to be replaced for different loads, and the device can adapt to most loads with rated current, especially load circuits below 64A.

Description

technical field [0001] The invention relates to a fast electric fire-proof current-limiting protection device. Background technique [0002] In recent years, electrical fire accidents in my country have been on the rise year by year. According to statistics, electrical fires account for as high as 30.2% of all kinds of fire accidents, of which serious and extraordinarily serious electrical fires account for 70% of the total number of major and extraordinarily serious fires. In the past three years, electrical fires caused by electrical faults have occurred frequently, resulting in huge personal casualties and property losses. Due to the complexity of electrification equipment in buildings, fires caused by electrical short circuit and overload are becoming more and more common, and related fire cases are also increasing. [0003] In actual circuits, fires caused by local high temperatures due to short circuit, overload, etc. are called overheating fires. The overheating typ...

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Problems solved by technology

[0007] 1. The load is different and the current is different. It is necessary to set different reference change rates, that is, thresholds, for different rated currents, and the versatility is poor;

[0008] 2. The rate of change calculated by this method is relatively large, and the noise will be amplified;

[0009] 3. The setting of the reference rate of change, that is, the threshold is affected by subjective factors. Usually, the reference rate of change, that is, the threshold, is artificially set to a constant value, which lacks reliability. If the threshold is set larger, the detection time will be prolonged; if the threshold is set smaller , there will be misjudgment

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