Multi-phase measuring device of lightning arrester and transformer based on FFT algorithm and method thereof

Abstract

The invention discloses a multi-phase measuring device of lightning arrester and transformer based on FFT algorithm and method thereof, and the device comprises a comparing circuit, four testing circuits being the same in structure, an analyzing control module and a wireless module; the comparing circuit comprises an optical coupling isolation circuit and zero crossing comparing circuit, one end of the optical coupling isolation circuit is connected to one phase of the A, B, C of the power transmission line while the other end thereof is connected to the input end of the zero crossing comparing circuit, the other end of the zero crossing comparing circuit is connected to the analyzing control module; the full current of the A phase, B phase, C phase and the N phase are monitored at the same time, the full current is transformed via Fourier to obtain the resistance current, which is analyzed to remove the interference to the capacitative current, the detection sensitivity is increased; the running state of the lightning arrester and transformer is monitored in on line mode at real time for reducing the non-scheduled outage and running accident; the recondition expense is reduced, the early failure signal and the continuous real time tracking fault evolution process of the lightning arrester and transformer are monitored.

Description

technical field [0001] The invention discloses an FFT algorithm-based multi-simultaneous testing device for lightning arresters and transformers and a method thereof, and specifically relates to the technical field of lightning arrester monitoring. Background technique [0002] The arrester is one of the important equipment of the power system. The function of the arrester is to protect various electrical equipment in the power system from being damaged by lightning overvoltage, operating overvoltage, and power frequency transient overvoltage. The types of arresters mainly include protection gaps, valve arresters and zinc oxide arresters. The protection gap is mainly used to limit the atmospheric overvoltage, and is generally used for the protection of power distribution systems, lines and substation incoming lines. Valve-type surge arresters and zinc oxide arresters are used for the protection of substations and power plants. They are mainly used to limit atmospheric overv...

AI Technical Summary

Problems solved by technology

In order to discover the hidden dangers of the arrester in time, it is necessary to monitor its operating status online. It is necessary to monitor the full current of the arrester and the transformer, and to monitor the internal insulation of the arrester and the transformer, so as to discover the working conditions of the transformer and the arrester in time. At present, the status of the arrester The main method of on-line monitoring is on-line monitoring. The current detection technology cannot realize the simultaneous detection of three-phase current and voltage, so that the working status of the arrester cannot be directly observed at the same time. In addition, the existing arrester monitoring devices do not have remote transmission function and need to be operated Personnel go to the site to read, which wastes time and energy. At the same time, it cannot be viewed intuitively, and the data cannot be viewed and analyzed efficiently. The situation of leakage current cannot be effectively predicted, and work efficiency cannot be effectively improved.

[0004] The zinc oxide arrester in normal operation is composed of capacitive current and resistive current. Since the distance between zinc oxide particles is very small, its equivalent capacitance is relatively large. Therefore, the capacitive current accounts for the main component of the total current; After aging, the main change is the resistive current (generally manifested as an increase in leakage). If only the total current is detected, the small change in the resistive current will be annihilated by the much larger capacitive point flow, and the detection sensitivity is very low. Early defects and failures are often not found,

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