Research On Key Technology Of Passive Wireless Temperature Measurement In Power High Voltage Switchgear

High voltage switchgear,as a widely used power equipment,directly faces customers,and its reliability of safe power supply has attracted much attention.In the long run,the equipment overheating will be caused by surface oxidation corrosion,loosening of fastening bolts,and aging of contact and busbar connection.If it can not be found and overhauled in time,serious equipment accidents will be caused.At present,the main temperature measurement methods commonly used in high voltage switchgear are infrared thermal imaging,pasted warm wax film and so on.But because most of the switch cabinet is KYN series,it belongs to closed combination equipment,the internal structure is complex and the components are blocked by each other.The temperature measurement technology of the traditional switch cabinet has some limitations.It can not directly obtain the corresponding infrared atlas by infrared thermometer,or can not directly observe the melting situation of the wax sheet in many positions,but also can not control the temperature change in real time,which leads to the overheating of the switchgear cabinet and even the fire,causing huge loss.As the demand for power supply reliability is getting higher and higher,it is of great practical significance to study a technology that can accurately measure temperature and real-time on-line monitoring of temperature changes.In recent years,with the rapid increase of power load,the author's work unit has caused a number of burning accidents inside the switchgear,resulting in large economic losses.In order to achieve accurate temperature measurement of high-voltage switchgear and real-time monitoring of temperature changes,this project designed and developed a high-voltage switchgear missed wireless temperature measurement system,and successfully applied to the substation under its jurisdiction.This paper first analyzes and compares the advantages and disadvantages of various types of temperature measurement technology,the research status of SAW temperature measurement technology at home and abroad and their respective defects,and determines the temperature of high voltage switchgear by wireless surface acoustic wave measurement.Secondly,according to the characteristics of the high-voltage switchgear,detailed hardware and software design is carried out.The hardware design part mainly designs the oscillation circuit,the mixing circuit,the frequency detection circuit and the data inquiry circuit to ensure accurate temperature measurement.Perform a detection of temperature changes.Finally,according to the previous operation experience,the key points of temperature measurement were identified,and the sensor placement scheme of different types of switchgear cabinet was determined,which improved the temperature coverage and effectiveness of temperature measurement.Aiming at the problem that absolute temperature algorithm is not sensitive to the alarm of switch cabinet temperature change at present,relative temperature algorithm is explored to reflect the operating state of switch cabinet equipment more accurately.After the optimized temperature measurement system is installed and applied in the field,the device has been running well for more than one year,which verifies the scientific,rationality and effectiveness of the temperature measurement system,and provides a referential technical model for solving the temperature measurement problem of the switch cabinet.