MPC-Based Multi-Inverter Power Control in Low-Inertia Power Systems

In a bid to make the electric grid more sustainable, there is a need to increase the integration of renewable energy resources at various locations in the grid. This move will reduce the total amount of physical inertia available from synchronous machines in the grid, resulting in the need for these resources to increasingly take on frequency response functions. In this paper, we propose a distributed model predictive based control method to coordinate multiple inverter-based resources in the grid. Under this control structure, the controller determines the optimal active power set-point for each inverter in the event of a disturbance in the system. In contrast to other control strategies, this controller does not constrain the inverters to behave like a traditional synchronous machine in responding to a disturbances. It instead leverages on the fast actuation of the inverters by virtue of the speed of its power electronic circuits. We demonstrate, by testing on the IEEE New England 39-bus system with integration of multiple inverter-based resources at different buses, that our proposed controller can coordinate these resources to provide an efficient frequency response under varying scenarios.