This paper proposes an effective sliding mode controller (SMC) for a grid-connected 7-level Packed U-cell (PUC7) inverter. The aim is to design a simple controller that deals effectively with the complex control problem of the PUC7 inverter (multi-objective control problem). The selection of the control actions is achieved according to the system state error at every sampling time regardless of the previous values, which makes the control technique model- independent. The control algorithm evaluates online two cost functions (one for each state error) which are derived based on sliding mode (SM) theory, and selects the optimal control input in order to satisfy the reaching conditions of the two cost functions. Compared to the existing solutions, the proposed SMC technique ensures lower average switching frequency by tuning the hysteresis bandwidth of the capacitor voltage error. The fast implementation, needless of gains tuning, and simple design procedure are the main features of the proposed algorithm. Simulation and experimental results are presented to prove the effectiveness of the proposed technique in controlling the PUC7 inverter with high dynamic performance and robustness against disturbances and parameters mismatch.
- grid-connected inverter
- Multilevel converter
- packed U-Cell inverter
- sliding mode control
ASJC Scopus subject areas
- Control and Systems Engineering
- Electrical and Electronic Engineering