Analysis and Optimization of Module Integrated MPPT Converter-Based Residential PV System
The power loss that results from mismatched power levels is critical to improving overall efficiency of the residential PV system. In general, a dedicated DC-DC converter with an extra distributed MPPT (maximum power point tracking) algorithm, used in a MIMC (module integrated MPPT converter), is connected to each panel to reduce the mismatch impact. However, even when using MIMCs, it is not always possible to guarantee all the panels work at their MPP (maximum power point) operation points. We have analyzed the characteristics of the MIMC-based residential PV, and derived the criteria for ensuring that all the MIMCs work at their MPPs. We propose an optimized MIMC system configuration to allow each of the PV panels to work at its individual MPP regardless of the mismatch case. Simulation and experimental results have validated the proposed system structure. The conventional NP balancing algorithms don't deal with switching loss reduction, because the redundant vector selection is based on a single objective. However, for high-power, high-frequency NPC power conversion systems, in addition to the NP balance, loss and noise reduction are also important goals. We have also developed a new SVM scheme based on the existing control algorithms, that can achieve multiple objectives at the same time.