Gain-Scheduled Structured Control in DC Microgrids

Power buffers are electronic converters that shield direct current (dc) microgrids from the effects of abrupt load changes. By promoting collective behaviors, distributed control solutions can improve the overall grid performance, as power buffers can collectively react to abrupt load changes. In this article, a novel gain-scheduled structured control scheme for power buffers is proposed. The control objective is to regulate both the stored energy and the input impedance of the power buffers in a distributed fashion, while guaranteeing, at the same time, the closed loop stability regardless of load changes occurring within predefined ranges. The proposed controller is expressed as a gain-scheduled state feedback law, whose coefficients depend affinely on the scheduling parameters. The structure of the controller gain is chosen to reflect the topology of the communication network implementing the distributed controller. In this article, the existing theory is extended to deal with such control problem, providing a novel strategy, which can be used to design gain-scheduled controllers for the considered class of structured feedback systems. Simulation results using a high-fidelity dc microgrid simulator verify the effectiveness of the proposed approach.