Linear Quadratic Tracker in Multi-agent System

This paper proposes a distributed secondary voltage control for microgrids based on a linear quadratic tracker (LQT). The controller in each distributed energy resource (DER) utilizes local measurements, nearest-neighbor communication, and the properties of the coupling complex impedance to implement the secondary control law. The control parameters are tuned to achieve the desired response speed by minimizing a cost function that includes the dynamic model as an equality constraint. The resulting optimal control is easy to design, and its effectiveness is verified through simulations of a microgrid test system in PSCAD/EMTDC and its performance compared to that of the well-established distributed averaging proportional-integral control method.