Intelligent online monitoring device and method for circuit breaker operating mechanism

Abstract

The invention discloses an intelligent online monitoring device and method for a circuit breaker operating mechanism. The intelligent online monitoring device comprises two displacement sensors, a baffle plate, a supporting plate, a hinge pin, a spring, a pull rod, an LC oscillation circuit, a shaping circuit and a CPU (Central Processing Unit), and is characterized in that the positions of the two displacement sensors correspond to the position of the supporting plate and the position of the end part of the baffle plate at a compression state of the spring, connecting lines at two ends of a detecting coil of each displacement sensor go through an iron core and are led to the LC oscillation circuit, the output of the LC oscillation circuit is connected with the shaping circuit, and the output of the shaping circuit is connected with a high-speed counting interface of the CPU. The frequency of the LC oscillation circuit is calculated through a count value of a high-speed counter within a set timing time, so that inductance of the detecting coil is acquired, thus the distance between each displacement sensor and the baffle plate is calculated, and deformation of the supporting plate and the baffle plate after energy storage of the spring is calculated. The intelligent online monitoring device acquires a static stress value of the operating mechanism by adopting the non-contact displacement sensors, and is free of mechanical abrasion and long in service life.

Description

technical field [0001] The invention relates to an intelligent on-line monitoring device and method for an operating mechanism of a circuit breaker, belonging to the technical field of on-line monitoring of circuit breakers. Background technique [0002] With the development of social productivity and the continuous advancement of science and technology, the demand for electricity has also increased dramatically, and circuit breakers are crucial control and protection equipment in power systems, and are also the most frequently operated equipment in the power grid. Therefore, it is of great significance to ensure the safe and reliable operation of circuit breakers. [0003] In order to ensure the safe and reliable operation of the circuit breaker, maintenance of the circuit breaker is often arranged. At present, the maintenance methods of circuit breakers can be roughly divided into three types, namely after-event maintenance, planned maintenance and condition maintenance. ...

AI Technical Summary

Problems solved by technology

A large number of statistical data show that under the combined effects of high static stress, corrosion and temperature for a long time, the performance of the parts of the operating mechanism will be greatly degraded, such as spring stress relaxation, detent and bracket distortion and shaft pin bending displacement, etc., resulting in Due to the degradation of mechanical properties, the circuit breaker cannot normally perform opening and closing operations, which reduces the ability of the circuit breaker to quickly break the large fault current, thus causing accidents

At present, relatively mature online monitoring systems are mainly aimed at the mechanical characteristics of circuit breakers. The detection methods mainly include stroke-time detection method, opening and closing coil current detection method, vibration signal detection method and image measurement. These online monitoring systems are aimed at The mechanical characteristics belong to the dynamic performance of the switchgear. If the circuit breaker is in the static state of closing or opening for a long time, the degradation of its static performance cannot be warned in time.

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