Conversion circuit for electronic type arc protection

Abstract

The invention relates to a conversion circuit for electronic type arc protection. The conversion circuit for electronic type arc protection comprises a photoelectric conversion circuit, an analog filter circuit, N comparators and a digital processing unit; the positive electrodes of the comparators are connected to N reference voltages having progressive increasing voltage values in one-to-one correspondence; the negative electrodes of the comparators are connected to output voltage of the analog filter circuit; and the digital processing unit is used for receiving N channels of switching quantity signals output by the N comparators in real time, recording the times when the N channels of switching quantity signals are changed, and taking reference voltage corresponding to the time when the switching quantity signals are changed as a sampling point for arc sampling. According to the conversion circuit for electronic type arc protection disclosed by the invention, an AD chip is not used; analog-to-digital conversion can be realized only by an analog comparator and the digital processing unit; the purpose of digitizing arc waveform is achieved; the circuit disclosed by the inventionis particularly suitable for fast arc signals having a huge dynamic range; and furthermore, the scheme in the invention has great advantages on the cost of the whole system.

Description

technical field [0001] The invention relates to the technical field of relay protection, in particular to a conversion circuit for electronic arc protection. Background technique [0002] Arc protection is a protection function specially designed to solve the personal safety of operators or prevent unexpected situations. Backup protection of components plays an important role. [0003] The existing 1st and 2nd generation arc protection implementation methods are comprehensive judgment of light and electricity, which cannot conduct quantitative analysis of arc light, but can only make qualitative judgments, which limits better analysis and research on arc light protection. Due to arc light The speed is extremely fast, and the analog gain of the arc light trigger point and the ambient light has a huge difference, so acquisition and digitization are extremely difficult. [0004] After retrieval, Chinese invention patent application CN 106410970 A discloses an arc light protec...

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Problems solved by technology

[0005] Although the acquisition and digitization of arc light is realized in the patented solution, because the arc light generation process is extremely short, for example, the time from 500Lux to 8000lux is at the subtle level, and the sampling frequency of the analog-to-digital converter needs to reach 10M sampling points / second The above can meet the production needs, but the price of the analog-to-digital converter with a sampling frequency of 10M sampling points per second is too high, which pushes up the cost of the arc sampling-conversion circuit, making it difficult to promote in the industry

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