Challenges and Prospects of Power Sharing Schemes in a Power Electronics Dominated Grid

Power electronics dominated grid (PEDG) consisting of multiple inter-connected distributed generation (DG) units are getting more popular because of their benefits in reducing the stress on main transmission lines, limiting line losses, and improving the efficiency and stability of the power system. Often a PEDG is comprised of several energy sources such as solar, wind, and energy storage devices. For that reason, optimal power sharing between all the sources is crucial to enhance the reliability and resiliency of the network. Hence, this paper provides comprehensive insights into the operation and working principles, limitations, and challenges of the power-sharing schemes employed in PEDG. More specifically, control laws of the droop, virtual synchronous generator (VSG), and Lienard and Consensus-based oscillators are briefly overviewed. In addition, the inherent drawbacks and challenges of existing power-sharing schemes are explained for inductive, resistive, and complex line impedances. Moreover, their performance under dynamic variations of the source availability, inverter power reserve, line losses, and generation costs are discussed in detail.