A control methodology for load sharing system restoration in islanded DC micro grid with faulty communication links

Communication-based distributed secondary control is extensively used in DC microgrids. Compared to centralized control, it can provide better voltage regulation and load sharing in microgrids. A conventional secondary control technique that converges the system to a common operating point is improved by using the control methodology to detect the communication link failure and stabilize the system operation during communication islanding. Recently, more robust control schemes have been proposed to improve resilience, but communication islanding has not been addressed at the secondary level control for which the system requires additional tertiary control. However, link failure is a possibility in the microgrid, so this paper proposes a control scheme at the secondary level to detect communication islanding. Communication islanding may lead the system to unpredictable behavior, which may cause the system to become unstable and may further lead to a cascading failure. The proposed control scheme sustains the stability and operation of a DC microgrid. Voltage and current observer works in a parallel manner with the proposed secondary control to achieve a correction term for global operating points. The proposed control scheme has been verified through analysis and simulation.