Robust Nonlinear Distributed Controller Design for Active and Reactive Power Sharing in Islanded Microgrids

Abstract

This paper presents a robust nonlinear distributed controller design for islanded operation of microgrids in order to maintain active and reactive power balance. In this paper, microgrids are considered as inverter-dominated networks integrated with renewable energy sources (RESs) and battery energy storage systems (BESSs), where solar photovoltaic generators act as RESs and plug-in hybrid electric vehicles as BESSs to supply power into the grid. The proposed controller is designed by using partial feedback linearization and the robustness of this control scheme is ensured by considering structured uncertainties within the RESs and BESSs. An approach for modeling the uncertainties through the satisfaction of matching conditions is also provided in this paper. The proposed distributed control scheme requires information from local and neighboring generators to communicate with each other and the communication among RESs, BESSs, and control centers is developed by using the concept of the graph theory. Finally, the performance of the proposed robust controller is demonstrated on a test microgrid and simulation results indicate the superiority of the proposed scheme under different operating conditions as compared to a linear-quadratic-regulator-based controller.

Review of Power Sharing Control Strategies for Islanding Operation of AC Microgrids

“…The distributed control is often applied to parallel converters [24], [32], [33], [90]- [93]. The instantaneous average current sharing is a typically distributed control for parallel converters.…”

“…The most advantage is that the DGs can share loads according to their increment costs. A robust distributed controller is designed for sharing active and reactive power in [93]. It use partial feedback linearization and ensure the robustness by considering structured uncertainties.…”

Nonlinear Controllers Based on Exact Feedback Linearization for Series-Compensated DFIG-Based Wind Parks to Mitigate Sub-Synchronous Control Interaction

“…EFL works by 'removing' nonlinearities via nonlinear feedback, and the transformed system is independent of the operating point. The EFL method has been widely utilized for designing controllers of converters for static compensators [29], electric vehicles [30], island microgrids [31], and photovoltaic systems [3]. This paper proposes nonlinear controllers based on EFL that could generate the regulated input signals for driving RSC and GSC switches to alleviate SSCI.…”

Enhanced Two-Stage Hierarchical Control for a Dual Mode WECS-Based Microgrid

“…In such a manner, the MG requires a type of control to allow it to meet several requirements, such as regulating voltage and frequency and avoiding the circulating currents between DGs [5]. When the MG operates connected to the main grid, both voltage and frequency postures can be regulated by the main grid because of the relative disparity The rest of this paper is arranged as follows: Section 2 describes the detailed structure of WECS-based MG.…”