Event-Triggered Model Predictive Control for the Inverter of a Grid-Connected Microgrid With a Battery-Supercapacitor HESS

This article proposes an event-triggered model predictive control (ET-MPC) method for inverters to connect dc microgrids with battery-supercapacitor hybrid energy storage systems (HESSs) to the grid. The procedure for creating the ET-MPC method is discussed in detail, including the system's state-space model formulation, the condition of grid connection under unbalanced grid voltage, the triggering condition setting, and the design of the controller. Introducing an event-triggered control strategy into the conventional finite-control-set MPC (FCS-MPC) can significantly reduce the number of control actions by eliminating unnecessary operations. This solves FCS-MPC's issue of a heavy computational burden while maintaining a satisfactory performance. The regulation performance verification of ET-MPC is conducted using digital simulation and hardware-in-loop (HIL) experiments. The comparison of the simulation and HIL results for ET-MPC and FCS-MPC shows the effectiveness of ET-MPC in connecting the dc microgrid to the grid; this new method has a similar performance to that of FCS-MPC but requires fewer switching actions and has a lower computational burden.