Three-Phase Interleaved Boost Converter With Internal Model Control to Drive Photovoltaics in Islanded Microgrids
Abstract
Photovoltaic (PV) systems based on renewable energy sources are the most common, and together with battery energy storage systems (BESS), they form a hybrid power supply. When riding through the islanded mode, the operation of the PV system consists of control for maximum power point tracking (MPPT) or generation curtailment as well as transitions between these functionalities. However, because the PV boost converter has a non-minimal phase response during power curtailment, slow dynamics and a narrow bandwidth may degrade its operation. In addition, it is necessary to operate with satisfactory power quality indices such as current ripple and total harmonic distortion (THD). To achieve actual islanded operation and power quality indices, the PV system should be driven by suitable converter-controller sets. This paper proposes a three-phase interleaved boost converter (TP-IBC) that reduces the non-minimal phase response effects and meets power quality requirements. To obtain more robustness, it proposes a control that responds efficiently to PV functionalities and sudden changes between them and is easy to tune using an internal model control (IMC). The MatLab/Simulink simulation results suggest that the proposed converter-controller set meets all these goals better than the conventional one based on a single-phase boost converter with a proportional-integral (PI) controller.