Research On State Perception And Evaluation Of Switchgear Based On Internet Of Things Technology

Nowadays,with the rapid development of the national economy,electricity consumption is also increasing,and the pressure on the operation and maintenance of power grid enterprises is also getting greater and greater.Failures of power equipment in the distribution network continue to occur frequently while operating and maintaining,especially in high-voltage switchgear.High-voltage switchgear plays an important role in the power grid,while the existing switchgear monitoring system is not perfect,highlighted by a single monitoring function,resulting in a lot of manpower,material and financial resources consumed in operation and maintenance.Therefore,this paper proposes the state perception and evaluation technology of switchgear based on The Internet of Things technology and develops a monitoring device,which can monitor the operating status of the switchgear in real time and provide a reference for the safe and stable operation of the switchgear.First of all,this paper analyzes the sensor technology,communication technology and computer technology in the key technologies of the Internet of Things,and designs a sensor circuit acquisition scheme composed of partial discharge sensor,ozone sensor and temperature and humidity sensor through theoretical analysis.The results show that the circuit acquisition scheme is more effective for the acquisition of signals in the switch cabinet,and the sampling of signals in the switch cabinet can be realized synchronously.At the same time,the 4G wireless communication circuit transmission scheme with FDD duplex mode and single antenna port and the One NET cloud platform database with data online monitoring,storage and processing functions are designed by using communication technology and computer technology.The results show that the communication circuit transmission scheme can remotely transmit the signal to the One NET cloud platform in real time,and the cloud platform can also monitor,store and process the data online after receiving the signal.Secondly,on the basis of the completion of the signal conditioning circuit,data transmission and cloud platform test of the state-sensing device,this paper builds a partial discharge test platform for the switchgear,and simulates the air gap discharge,side discharge and needle plate discharge of the switchgear.The state sensing device was used to collect the detection parameters of the three kinds of discharge conditions in the switchgear,and the spectrum map(number of discharges,discharges,discharge phase)was drawn through the data stored in one NET cloud,and the results showed that the discharge amount gradually increased with the increase of the test voltage along the surface discharge,and the discharge mainly occurred near 90 degrees and 270 degrees,and the positive period of discharge and discharge times were greater than the negative half cycle.In the case of air gap discharge,the initial discharge is relatively strong,the discharge is high,the discharge mainly occurs near 90 degrees and 270 degrees,and the positive period and negative cycle discharge and frequency are basically the same.In the case of needle plate discharge,the discharge amount increases with the increase of the test voltage,and the discharge mainly occurs in the negative half cycle and is between 200 degrees and 300 degrees,and there is a small discharge in the positive half week.Finally,the actual state of the switchgear is evaluated using the signal collected by the sensing device as a variable.Taking the local discharge,ozone,humidity,temperature,and environmental humidity as the parameters,and dividing the grade into five comment levels of excellent,good,attention,abnormal,and serious,the membership function of the subordinate variable combining semi-trapezoidal and semi-ridgeform is established,and the fuzzy theoretical evaluation method of the weight set of the index weight is determined by finding relevant literature and a large number of examples in the experimental process,combined with the evidence reasoning algorithm,a set of comprehensive assessment methods for the state of the switch cabinet combined with fuzzy and evidentiary reasoning is given.The evaluation results show that the comprehensive evaluation method can be applied to the state assessment of the switchgear,and the evaluation results are in line with the actual situation.