The Research On Temperature Acquisition Technology And Device Development For Switch Cabinet Breakr Contact

As one of the most important equipment for power plant and substation,switchgear stability,safe operation is directly related to the performance of the entire power system.In the long-term operation,the switchgear circuit breaker contacts due to poor contact,mechanical wear and air corrosion and other reasons leading to their increase in the block,so that the rapid increase in heat.If it is not found and dealt with in time,it will cause serious safety accidents.In order to ensure the safe operation of the switch cabinet system and avoid the serious safety accident caused by the thermal fault,a set of on-line temperature monitoring device is designed and developed by a large number of methods.In this paper,starting from the whole,according to the design requirements,I put forward a safe and reliable design of the real-time monitoring system of the contact temperature for the switch cabinet breaker.In this paper,the temperature measurement device uses fiber Bragg grating as the temperature sensor.As the fiber Bragg grating with temperature strain cross-sensitivity,in order to avoid cross-sensitive effects,this paper uses ceramic-coated fiber grating sensor,and in order to ensure the uniformity of the sensor's temperature measurement,the sensor is fixed in the middle of the static contact.This paper focuses on the principle and design of fiber grating wavelength demodulator,and the key of the temperature measurement is to obtain the offset of the central wavelength,In order to obtain the accurate center wavelength offset,this paper uses the five-point center wavelength shift algorithm for calculation.For the switchgear circuit breaker contacts always work in high voltage,high current and strong magnetic field of harsh environments,fiber grating sensors using optical fiber transmission signal,the utility model solves the problem of high voltage insulation isolation and improves the reliability and safety of the device.And the device uses RS485 bus communication technology to achieve fiber optic grating temperature measurement system to the integrated controller between the data communication.And the man-machine interface is designed by using the DGUS touch screen,which is used to display the real-time temperature and working state of each contact,and realize the over temperature alarm.After finishing the hardware and software of the device,I test the device by different test methods and get detailed test results for each function of the device.At the end of the paper,I summarize the research contents and the work done,and make a prospect for the improvement of the device.