An Improved Fault Location Method of DC Distribution System Based on EMD

The line resistance of the DC distribution system is small and the fault propagation speed is fast. In addition, the fault characteristics influenced by the converter control strategy are not obvious. Using traveling waves to locate faults is a popular research area in DC distribution system protection in recent years. This article provides a detailed explanation of the principle by using the traveling wave approach to locate faults, and deduces the traveling's characteristics of propagation when fault voltage is in and out of the protection zone in the linear model network. A signal analysis method based on EMD (Empirical Mode Decomposition) is introduced for the extraction of wave heads. Using EMD to break down temporary fault signals and extract the first IMF1(inherent modular function). Then, the fault wave head reaches the monitoring point at the corresponding moment of the mutation point, which may be determined by deriving the IMF1 component. Finally, a dual ended single pole distribution network model was built based on the PSCAD simulation environment, and the fault location method was verified.