Electrical Quantities Determining Method for Extrahigh Voltage Lines Setting Calculation Considering Fault Types Prediction

The offline setting calculation of the EHV line needs to consider a large number of operating conditions to determine the electrical quantities used in the setting calculation, among which the fault type is one of the factors affecting the number of conditions. To improve the efficiency of setting calculation, this paper proposes a method of determining the electrical quantities used in the setting calculation of EHV line based on fault type prediction. First of all, the commonly used electrical quantities in the setting calculation of EHV line are summarized. Then, their expressions are deduced based on the node impedance matrix, and their variation rules with the fault types are also analyzed. According to the results, the electrical quantities used in the setting calculation can be classified into four types, named irrelevant, explicit, difficult and conditional separately. Based on the type of the electrical quantities used in the setting calculation and the characteristics of their variation rules, a method of determining the electrical quantities used in the setting calculation based on fault type prediction is proposed. At last, using the IEEE 39-node system to prove that the method of this paper can improve the efficiency of setting calculation under the premise of accuracy.