Research On The Electromagnetic Coupling Characteristics And Protection Of Substation Electronic Equipment Key Ports

The number and types of electronic devices are more and more in the substation.The realization of the substation important function is more and more dependent on the electronic equipment of the weak electricity system.The characteristics of electronic equipment are many components and complex structure.The ability to resist electromagnetic disturbance is poor.And,with the implementation of the "smart grid"plan,on-site installation of intelligent electronic device is mandatory.It makes the strong and weak electricity system more concentrated,all kinds of electronic equipment closer,and the main loop coupling stronger,which makes the energy of electromagnetic disturbance flow to the internal through the electronic equipment port extremely easily and causes abnormal work or even damages the equipment.This is a serious threat to the safe and stable operation of the power grid.This dissertation is supported by the National Natural Science Foundation of China"Fast Time Domain Electromagnetic Transient Simulation Technology of the Large Scale Multi-conductors System"(51407073)and the Fundamental Research Funds for the Central Universities(13MS63)"Research on EMC of UHV substation secondary equipment",and emphatically carries out the research on the electromagnetic coupling characteristics of electronic equipment key ports,proposes the immunity requirement of the intelligent component and communication equipment on substation,calculates the amount of electromagnetic coupling at key ports of electronic equipment in real environment,discusses the protective measures against electromagnetic disturbance.The main contents are as follows:Aiming at the installation position of intelligent component in substation,the measurement and feature analysis of electromagnetic environment on the steady state and transient state are carried out in 220kV smart substation,220kV substation,500kV GIS substation,UHV 1000kV GIS substation and high-pressure experimental hall.In addition,the immunity requirement of the intelligent component and communication equipment on substation is proposed.Partially adopted by industry standards.Through establishing the multi-port macro model of the power cable,model of the transformer and the partial element equivalent circuit technique(PEEC)model of ground net,gets the whole model of high voltage test system.The coupling characteristics of the disturbance voltage generated by the power port of the intelligent component of the transformer are analyzed.The common mode voltage and differential mode voltage of high potential incoming current and the ac power supply port under different excitation voltage in full lightning impulse test are calculated.The calculated values compare with the measured,and the effectiveness of the method is proved.Based on the multi-conductor time domain finite element method with a parameter of frequency-dependent impedance,the radiation field coupling characteristics of E1 communication cable are carried out.The result reveals the coupling characteristics of the signal port affected by lightning in the telecom room.Using a new test method of signal ports,summed up the regularity of the relationship among the bit error rate,field strength and the line length.Tests beyond standard were also done for other types of signals,which predict the working state for their work in more harsh environments.Circuit models of surge protector and TVS diode are established and the protective performance of the surge protector,gas discharge tube,filter,TVS diode and the combination are analyzed.Comparing the effect of different protective measures,the protective measures for the ports of electrical equipment in the substation are discussed.