A Novel Fault Transient Analysis Method for DC Lines Considering Multiple Refractions and Reflections of Traveling Waves

A precise transient electrical quantity analysis method for DC line faults is an important basis for protection setting adjustment and power equipment parameter design. However, the transient process of faults in DC transmission systems is complex, and the analytical calculation is difficult. Most of the existing analysis methods can only analyze the fault electrical quantities during the initial traveling wave (TM) stage. Based on the traditional initial TW fault analysis method, this paper analyzes the multiple refractions and reflections of TWs after the line fault, and proposes an analytical calculation method for the entire fault process electrical quantities without increasing the calculation matrix dimension. Through simulation tests, the accuracy of the proposed algorithm is fully demonstrated.