The EMC Scheme And Temperature Control Optimization Of 220kV AIS Substation Intelligent Control Cabinet

The 220kV AIS substation is currently the most stocked substation in our country.The intelligent control cabinet in the substation is placed underground in the switchyard with electromagnetic and harsh temperature environment,causing it to refuse to move,malfunction,and has a long service life.Long phenomenon.After investigation,it is found that the steady-state and transient electromagnetic field strengths in some areas of the 220kV AIS substation exceed the maximum allowable interference immunity requirements of the secondary equipment of the substation,and the current working environment of the equipment in the intelligent control cabinet is poor,and the temperature within a year can be extremely poor.Reaching 70℃ affects the service life of the equipment.Therefore,it is necessary to study the electromagnetic compatibility(EMC)scheme and temperature control optimization of 220kV substation intelligent control cabinet to reduce the failure rate of 220kV substation intelligent control cabinet and ensure its service life.The main research work of the thesis is as follows:(1)Research on steady-state electromagnetic environment of 220kV AIS substation.A three-dimensional model of the substation was constructed using a three-dimensional simulation platform,and its spatial steady-state electromagnetic field distribution was obtained.The average error of the comparison between the simulation test results and the field test data was 4.59%,which verified the accuracy of the simulation test.Further research shows that the worst electromagnetic environment in the substation is located in the bus-intensive area of the switching field,and the average electromagnetic field strength of the switching field exceeds the maximum anti-interference ability of the control cabinet.(2)Research on transient electromagnetic environment of 220kV AIS substation.Use simulation software to conduct transient arc modeling,study the severe transient phenomena of disconnecting switch opening and circuit breaker reclosing operations,obtain corresponding transient arc test results,and use the test results as the excitation source for the intelligent sink.Control the small room for electromagnetic interference distribution test.The test results show that although the transient interference of the isolating switch is the strongest,the indicating value reaches 3.56pu and the overcurrent reaches 230.22kA,the recloser of the circuit breaker closer to the intelligent control cabinet has the greatest impact on it,and the indicating value reaches 21.278kV/m,6.9 kA/m,exceeding the maximum immunity of the equipment.(3)Research on EMC optimization scheme of intelligent HSBC small room.Aiming at the steady-state electromagnetic environment,through the single factor test of the current installation path of the intelligent control cabinet in XYZ three directions,the best installation path of the intelligent control cabinet is obtained.The field test results of the EMC scheme show:new installation on the 220/110kV side Compared with the previous installation path,the electromagnetic field intensity of the path is optimized by 65.59%and 16.9%,respectively,and the average electromagnetic field intensity is 449.5V/m,3.86A/m and 5 1 3.6V/m,1 6.35A/m,respectively,which meets the normal working electromagnetic field of the intelligent control cabinet.Environmental requirements.Aiming at the transient electromagnetic environment,through the orthogonal experiment of the shielding effectiveness of the intelligent control cabinet cabinet,the transient EMC optimization scheme is obtained with ferroalloy material,double-layer shielding layer,cube chamber type.The simulation results show that the overall electromagnetic field shielding effectiveness is optimized compared to the original chamber 41.45%,reaching the equipment immunity standard.(4)Research on optimization of temperature control strategy for intelligent control room based on BP-PID.By analyzing the physical characteristics of the intelligent control cabinet,using mathematical modeling method to derive the transfer function of thermal disturbance and cabinet temperature,and constructing the intelligence with actual temperature,expected temperature,difference between actual and expected temperature and step response as input BP-PID temperature control system model of HSBC small room.The simulation results show that under the same interference,the adjustment time of the BP-PID controller after interference is about 800s,and the overshoot is 5.2%.Compared with the control effect of the existing controllers monitored on site,the adjustment speed is increased by 83.16%.