Single-phase Adaptive Reclosure Of Transmission Line Based On HHT Marginal Spectrum Entropy

Automatic reclosing device is one of the principal measures to guarantee powersystem security and stability operation, and has been widely applied in the Ultra-HighVoltage/Extra-High Voltage(UHV/EHV) power system. However, the conventionalautomatic reclosing device can not distinguish permanent fault and temporary fault,reclosing on the permanent fault maybe produce a certain degree harm on powersystem and severe cases may cause the system to lose stability. So, if we can correctlyidentify the nature of the fault before the device is closed, then decide whether or notto perform reclosing, it will be important to ensure the high reliability of power supplyof the system. In this paper, I used Hilbert-Huang Transform(HHT) to study a newfault recognition algorithm of single-phase adaptive reclosure of transmission line.Firstly, I compare several existing domestic and foreign mainstream adaptivereclosing identification algorithm, point out the shortage or scope. At the same time, Istudy the dynamic characteristics of the primary and secondary arc and the restrikecharacteristics of the secondary arc, and then use the electromagnetic transientsoftware ATP/EMTP to make a simulation analysis on fault phase for EHVtransmission line, in order to gain the corresponding single-phase fault phase voltagewaveform for EHV transmission line with shunt reactor.Secondly, I use the HHT marginal spectrum entropy algorithm to makecorresponding transient analysis on EHV transmission line fault phase signal, then getinvolved in in-depth discussion of the marginal spectrum entropy of signal frequencycomplexity, and the ability of the marginal spectrum entropy for characterizing infrequency domain and the applicability of the power signal analysis, while givingdetailed calculation steps of marginal spectrum entropy algorithm.Thirdly, The frequency complexity of fault phase voltage is analyzed with HHTmarginal spectrum entropy. In transient fault, after tripping the circuit breaker,transient high-frequency component of voltage of the fault phase is relativelycomplicated before extinguishing the arc, and the entropy is large; While in permanentfault, the high-frequency component decays fastly and tends frequency, and theentropy decreases rapidly.Finally, by using strong advantage of HHT marginal spectrum entropy on therecognition of the complexity of signal frequency in frequency domain, this paper proposes a new adaptive single-phase reclosing criterion method, at the same timemakes a great deal of simulation verification on different grounding fault points,different fault types and the fault condition with different size of grounding resistance.The results show that this method is able to recognize different fault properties withhigh accuracy, and its speed of recognition is superior to other methods, while it is notsubject to the restriction of other conditions.