Design and Comparison of Different Types of Synergetic Controllers for Islanded DC Microgrids

In this paper, different types of synergetic controllers (SCs), such as simple SC, piecewise linear function form of SC, linear synergetic controller, improved synergetic controller with terminal SC, and fast terminal SC have been designed and applied to an islanded DC microgrid. To be able to make the design of the controllers independent from system component values, a generalized mathematical method has been derived for all power electronics-based subsystems of the microgrid system. A small-scale DC microgrid has been designed and implemented to verify experimentally the robustness of the control law from the different synergetic controllers. Moreover, a generalized synergetic controller design approach has been derived in this paper for the islanded DC microgrids. The obtained results from both simulation and experiment tests have been compared and included in this paper. It is concluded that definition of macro variables is affecting robustness and tracking performance of the designed controllers.