SF6 breaker electrical endurance monitor system based on weak signal processing

Abstract

The invention relates to an SF6 breaker electrical endurance monitor system based on weak signal processing. The SF6 breaker electrical endurance monitor system based on the weak signal processing is mainly composed of portions of a signal conversion module, a range choosing module, a filtration module, an A / D (analog to digital) module, a signal processing module and the like, wherein the signal conversion module comprises an operational amplifier with a low bias current, completes conversion from a current signal to a voltage signal, and outputs the voltage signal to the filtration module, the range choosing module comprises a plurality of dry reed relays, and completes range automatic switching when a wide dynamic signal is input, the filtration module comprises an integrated filter, completes filtration of an output signal of a voltage conversion module, and outputs the output signal to the A / D module, the A / D module comprises a 24 bit A / D convertor, completes conversion from an analog signal to a digital signal, and outputs the digital signal to the signal processing module, and the signal processing module completes reading of the output signal of the A / D convertor, digital filtration, liquid crystal display and communications with an upper computer.

Description

technical field [0001] The design of the invention relates to the on-line monitoring of switchgear in the electrical field of electric power system, in particular to the on-line monitoring of the electric life of a high-voltage SF6 circuit breaker. Background technique [0002] With the continuous development of the power system, the capacity of the power system is increasing day by day. As an important switchgear in the power system, SF6 gas is used as the insulating medium and arc-extinguishing medium of high-voltage circuit breakers due to its excellent insulation properties, so that SF6 circuit breakers occupy an absolute advantage in power systems of 72.5kV and above. It plays a dual role of control and protection for the power system. The electrical life refers to the continuous breaking ability of the circuit breaker without maintenance, that is, the amount of wear of the contact material that is burnt out. The electrical life diagnosis of SF6 circuit breaker refers...

AI Technical Summary

Problems solved by technology

However, the degree of electrical wear of the contacts under different short-circuit currents is different, and the amount of wear and the magnitude of the short-circuit current are not linearly related.

It is not enough to judge the contact burning loss only by the accumulated breaking current

Therefore, judging the amount of contact burnout should take into account the different amounts of wear caused by breaking different short-circuit currents each time, which brings great difficulties to the electrical life detection of SF6 circuit breakers.

Therefore, it is necessary to innovate the existing electrical life detection status, not only rely on the breaking current, but monitor and evaluate the electrical life of the circuit breaker by reflecting the ablation status of the arc contact of the SF6 circuit breaker, so that it is expected to obtain a more accurate The results of electrical life monitoring make up for the shortcomings of no effective electrical life monitoring technology and methods for high-voltage SF6 circuit breakers at home and abroad, and provide theoretical and technical guidance for the upgrading of high-voltage SF6 circuit breaker intelligent products

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