Fast Data-Driven Predictive Controller for Multilevel Cascaded H-bridge Inverters with Faulty H-bridge cells

In this paper, a data-driven predictive controller (DDPC) with a fast closed-loop response and able to deal with failed H-bridge cells is proposed for multilevel cascaded H-bridge inverters. The proposed strategy uses multiple dynamic structures (MDS) and the measured current value for closed-loop control. Each dynamic data is a control signal associated with two current responses and derived by a PI-controller. In a classic DDPC, all dynamic data are stored in a single dynamic structure (SDS) independently of the operating condition. This results in a mixing of dynamics and increases the risk of using dynamic data at the wrong operating condition. In addition, without an adequate initialization at a slow update rate, the controller will require a period of time to modified SDS and characterize the new operating condition after the fault occurs, which results in a large transient time. To obtain a fast closed-loop response, an offline initialization algorithm is used to define MDS. With a reliable MDS, simulation results show that the proposed DDPC based MDS achieved a fast transient and balanced steady-state current response during startup and post-fault operations.