Hierarchical control of the DC microgrid with improved reliability

DC Microgrid takes an important role in the use of renewable energy inside houses or rural areas since the penetration of DC sources and the increase of DC loads. However, there are reliability issues in abnormal situations because the protections used in DC components are very slow in their response which can cause the blackout of the system. Normally, DC microgrids are controlled using a three-level hierarchical control, being the secondary level the responsible of the DC bus regulation through the elements connected. To manage difference power in the DC bus, the DC microgrid generator and storage elements must respond delivering or consuming that power but when this difference is higher/lower than the limits of the system, it can not be achieved. In this work, a load control is proposed for a DC microgrid which allows increasing the number of the agents involved in the DC bus regulation and improving the reliability of the system. A simulation is implemented in MATLAB/SIMULINK which shows the dynamical responses of the elements in a real operation for a day. The simulation results show a good response when the load power consumption is greater than the generated energy, making the load disconnect and connected once the DC bus regulation reaches the reference value.