Modelling and Control of DC Microgrids in Residential Buildings

Microgrids are considered as one of the most promising directions for the future of power systems. A major point in the characterization of a Microgrid is its ability to operate isolated from the main grid (islanded mode). However, the management strategy to allow such operation still poses a significant challenge in the implementation of these systems. The focus of this work is the behaviour of the distribution grid of a large-scale residential building during grid-connected and islanded modes, especially in terms of the control strategy to maintain a stable and uninterrupted supply of electricity.We developed aplatform for simulating a DC Microgrid’s (DCMG) long-term operation using a PSCAD model. This model allows for the simulation of a residential DCMG, targeting its energy management to maintain power balance under various conditions, including during islanded operation. This work discusses the control strategy used to maintain the voltage level at the distribution bus within a 5% limit of it’s rated value. For a theoretical building, the model yielded 2 hours of unlimited supply, and extra 4 hours of critical-load only. The results indicates that the proposed control strategy allows for adequate independence and stable operation during loss of grid connection.