Modern controller approaches for stabilizing constant power loads within a DC microgrid while considering system delays

Requirements and challenges associated with the microgrid are primarily focused upon controller design, communications, standard compliment, and medium voltage power converter design. The growth of power electronic load regulation creates circumstances for constant power load behavior to arise in microgrid power systems. Constant power loads have an inherent destabilizing effect where linear and nonlinear control approaches have been proposed to resolve this problem. In this article, a set of powerful, linear modern control approaches are used to account for unstable poles integral to the constant power load and non-minimum phase zeros provided by system time delays. An examination is conducted by using model matching techniques to handle the negative incremental impedance of the load and time delay developed between the local measurement and controller action to deliver power to the load.