Model Predictive Current Control of Four-Level Inverter and Modulation With Two Capacotors

This paper proposes a three-phase four-level inverter topology that improves on the original ANPC inverter by generating four voltage levels using only two capacitors. The proposed topology does not have redundant switching states associated with each voltage level. To achieve this, a current prediction modulation strategy is proposed since conventional modulation techniques cannot fulfill this requirement. This strategy not only maintains stable capacitor voltage but also controls the output current. To verify the proposed theory, we constructed a prototype device with a power rating of 600W. The experimental results demonstrate that the proposed three phase four-level inverter maintains excellent steady-state performance and fast dynamic response even when only two capacitors are used.