Algorithm for fault detection and localisation in a mesh-type bipolar DC microgrid network

• Published in: IET generation, transmission & distribution Vol. 13; no. 15; pp. 3311 - 3322
• Main Authors: Bhargav, Reddipalli, Bhalja, Bhavesh R, Gupta, Chandra Prakash
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 06.08.2019
• Subjects: aforementioned DC microgrid network; bipolar system; calculated value; currents; DC distribution system; distributed generators; distributed power generation; estimated parameters; exact location; external fault; fault currents; fault detection; fault diagnosis; fault location; ground; internal fault; local voltages; localisation; low‐voltage level; mesh‐type network; method detects fault; pole‐to‐pole voltage; power transmission faults; power transmission protection; pre‐defined threshold values; Research Article; time 1.25 ms; V mesh‐type bipolar DC microgrid network; variable fault resistance; voltage 1200.0 V; DC distribution system; fault diagnosis; bipolar system; voltage 1200.0 V; pole-to-pole voltage; fault detection; fault currents; aforementioned DC microgrid network; distributed power generation; internal fault; V mesh-type bipolar DC microgrid network; currents; local voltages; power transmission faults; power transmission protection; calculated value; external fault; distributed generators; low-voltage level; estimated parameters; fault location; exact location; localisation; variable fault resistance; pre-defined threshold values; method detects fault; time 1.25 ms; mesh-type network; ground
• ISSN: 1751-8687; 1751-8695; 1751-8695
• DOI: 10.1049/iet-gtd.2018.5070

This study proposes a new method to detect and locate the fault in a DC distribution system in the presence of distributed generators. As the mesh-type network provides good continuity of service during faults and the bipolar system transmits high power at low-voltage level to the end user, the proposed scheme has utilised 1200 V mesh-type bipolar DC microgrid network. The proposed scheme detects a fault by comparing the calculated value of fault current and pole-to-pole voltage with the pre-defined threshold values and then distinguishes internal or external fault based on an estimation of line parameters. In case of an internal fault, the estimated parameters yield the exact location of the fault. The modelling of the aforementioned DC microgrid network has been carried out in PSCAD/EMTDC environment and various faults involving pole and ground have been performed with variable fault resistance and location. The simulation results clearly indicate that the proposed technique is not only capable to detect the fault rapidly but also able to disconnect the faulty section speedily (around 1.25 ms). As the proposed method detects fault by utilising local voltages and currents, its reliability is better than the previous algorithms.