A robust control strategy for a single‐phase grid‐connected multibus microgrid based on adaptive sliding mode control and dynamic phasor concept

Abstract

Due to the increasing development of distribution networks, the need to use clean energy resources, and the existence of different single-phase and three-phase consumers, the maximum use of both single-phase and three-phase distributed generation (DG) units has become crucial. However, the presence of DG units in microgrids (MGs) requires efficient control strategies, for power control and voltage regulation, to achieve a rapid and proper dynamic response with respect to external disturbances and uncertainties. In this paper, in order to improve the dynamic and steady-state performance of an unbalanced multibus microgrid including inverter-based single-phase DGs, a robust control strategy is proposed for controlling the active and reactive power of DGs. The proposed control scheme is composed of a current controller based on an adaptive sliding mode control method in a virtual synchronous dq reference frame, to control the single-phase inverter output current, and a PI controller to regulate the voltage magnitude of the generation buses connected to DGs. In the proposed control structure, each single-phase inverter is controlled as a virtual balanced three-phase inverter, based on the dynamic phasor concept that makes decoupled control of the active and reactive powers of single-phase inverters possible. In order to evaluate the validity and effectiveness of the presented control structure, a multibus single-phase MG containing several inverter-based single-phase DG units has been simulated in MATLAB software environment, and the performance of the proposed control scheme has been investigated for various scenarios of parametric uncertainties and external disturbances.