Coordinated control and dynamic optimization in DC microgrid systems

It is challenging to continuously maintain an optimal operation in microgrids, especially with intermittent renewable energy resources and dynamic load profile. Proper coordination between hardware-based control and software-based optimization is required to improve the overall system performance in these conditions. A novel methodology is introduced here to control voltage and current simultaneously in real time, as well as optimally reconfigure a DC microgrid system as the operating conditions change. To do so, a dual-layer control hierarchy is designed to facilitate autonomous control and its optimization. The primary layer is implemented using an adaptive voltage droop scheme to achieve optimal load sharing. The secondary layer performs dynamic optimization to compute optimal droop gains based on a disturbance driven control process. The simulations and experimental validations for the proposed scheme demonstrated successful performance.