Energy management strategy for AC/DC microgrid

摘要

This paper proposes a grid connected AC/DC microgrid to reduce the processes of multiple conversions in an individual AC or DC microgrid. The hybrid grid consists of both AC and DC networks connected by a bidirectional AC/DC converter. Wind generator, AC loads and utility are connected to the AC bus whereas PV, energy storage system (ESS) and DC loads are tied to the DC bus. The coordination control algorithms of supervisor controller are proposed for smooth power management between AC and DC links and for stable system operation under various generation and load conditions. In this paper, a flexible supervisor controller is developed for a grid connected AC/DC microgrid, where the power flow in the microgrid is supervised based on demanded power with maximum utilisation of renewable resources and ESS. So, the objective of this paper is to use supervisory controller to control the transferred power from AC bus to DC bus and vice versa and control the charging/discharging power of the ESS to reduce the purchased power from the grid or to increase the sold power to the grid with respect to the load demand. The microgrid has been modelled and simulated using MATLAB Simulink. The simulation results show that the system can maintain stable under load variations.