Lyapunov-Function Based Predictive Approach for Load Voltage Control of Four-Leg Inverter with an Output LC filter

The recent success of finite control set model predictive control (FCS-MPC) in different power electronic converter control has motivated numerous research investigations into the stability and robustness of model predictive controllers. One critical issue arising from these works is to ensure the close-loop stability of the system. This issue has motivated this research on the stability of FCS-MPC in converter control. This paper investigates an alternative predictive controller implementation for four leg converter with an output LC filter, which allows an explicit characterization of the stability region of the closed-loop system and also leads at the same time to a reduced computational complexity placed on the controller. In the present analysis, using the Lyapunov's stability theory, it is mathematically shown that the overall system remains globally stable and all signals of the closed-loop dynamics are uniformly and ultimately bounded and the voltage control errors converge to a neighbourhood of the origin. Finally, experimental results are presented which clearly demonstrates the stability and the computation time reduction mentioned above.