Chapter 9 - Energy management techniques to enhance DC-bus voltage transient stability and power balancing issues for islanded DC microgrids

Abstract

The microgrid is one of the emerging fields in modern power systems to support the increasing power demand when compared with the conventional utility grid owing to the utilization of renewable energy resources (RESs). A DC microgrid is proposed in this chapter to utilize the advantages of RESs while reducing greenhouse gasses emission. The proposed DC microgrid consists of hybrid RESs, for example, a solar photovoltaic unit and a wind energy system, battery energy storage systems (BESS), and DC loads. For controlling the output power of the microgrid component, each component has its own DC-DC or AC-DC power electronic converter excluding the demanded DC load. Therefore, each module of the DC microgrid is accurately modeled, and a classical proportional integral (PI) controller is designed to obtain efficient operation of the microgrid. The key aim of this chapter is to maintain a stable standard DC-bus voltage and a proper power balance of the proposed DC microgrid under different operating conditions. Hence, to augment the power balance while keeping constant common DC-bus voltage in the DC microgrid, an efficient energy management control algorithm is also proposed in this chapter to give a command to the BESS and RESs efficiently. The proposed controller for each component of the DC microgrid is designed based on a decentralized manner where the communication is not required for optimal operation of the proposed DC microgrid. Finally, to show the effectiveness, the proposed DC microgrid along with the energy management control strategy is implemented in the MATLAB/SIMULINK platform.