8. Synthesis of Robust Virtual Inertia Control

Regarding the previously elaborated inertia control techniques, they are not explicitly designed to deal with the effect of high uncertainty and disturbance. Thus, it is difficult to achieve a suitable trade-off between robust and nominal performances. In adaptive control techniques, the uncertainty formulation may not be appropriately included in the control design process. As a result, it is difficult to ensure the simultaneous robust performance and stability of the virtual inertia control in the presence of bounded modeling errors. Due to the capability of uncertainty formulation in its control synthesis, the robust control technique successfully resolves the concerned problem. Compared with the adaptive control theory, the robust control theory is static rather than adapting to measurements of variations. Subsequently, the robust controller is specially designed to operate assuming that certain varibles will be unknown but bounded. This chapter presents the application of robust uncertainty modeling theory for designing the H∞ robust virtual inertia control system in the presence of high renewable energy sources (RESs)/distributed generators (DGs) penetration. Practical constraints and system uncertainties are appropriately considered during the robust synthesis process. The H∞ robust control is used via a developed linear matrix inequalities (LMI) algorithm to reach an optimal solution between nominal and robust performances for design objectives. The robustness and performance of the H∞-based virtual inertia controller are executed along with different sets of severe parametric uncertainty and external disturbance. The closed-loop system is verified through a nonlinear control system under the critical operating scenarios of uncertain control parameters with high RESs/DGs penetration.