Control of a DC microgrid under dynamic load condition

A dc microgrid is a controllable electric power system that integrates renewable energy sources, storage and dc load. Stable operation of dc microgrid is ensured by the bus voltage stability. The most important control technique for dc bus voltage regulation being the droop control strategy which does not require any communication there by ensuring high reliability. However, the conventional droop control technique ignores the load dynamics causing undesirable voltage fluctuations leading to failure of the microgrid system. In this paper, a novel control strategy is presented in which the conventional droop control is modified taking into account the load dynamics. The performance of proposed control strategy is compared with the conventional voltage droop control. The fluctuations in the dc bus voltage which is the major cause of voltage instability of the dc microgrid is compared for the two control strategies under dynamic load conditions. The stable operation of the microgrid is enhanced using the proposed strategy which is very significant as it is in autonomous mode.