Fault Detection in DC Microgrid Based on the Resistance Estimation

Evaluation toward the line parameter-based fault detection technique is an attractive option due to the limitations associated with the conventional differential and overcurrent protection schemes, mostly during a high resistance fault situation. The fault detection strategy based on the line parameter can be exploited using the resistance instead of directly taking the decision from voltage and current. In this article, the proposed technique is focused on estimating the resistance and detecting the fault even during high resistance fault case. Resistance is estimated using the local measurements available at the bus. After that, the sign of the estimated resistance is compared at both ends of the line segment to detect the fault and the use of the sign of resistance eliminates the time synchronization issues. The proposed method is capable of detecting the fault in radial as well as ring configuration dc microgrid. A ring main dc microgrid system is simulated using the EMTDC software to validate the proposed technique. The performance of the proposed approach is also validated using a dc microgrid hardware setup and tested for numerous situations. The results obtained from simulation and experiment verify that the proposed method accurately detects the faults (close in fault, high resistance fault) in the dc microgrid.

Automated summary

The evaluation of the line parameter-based fault detection technique is an attractive option to overcome limitations of conventional protection schemes during high resistance fault situations. The proposed method focuses on estimating resistance to accurately detect faults in radial and ring configuration dc microgrids. Simulation and experimental results validate the effectiveness of the technique in detecting faults accurately.