Maximum Power Point Tracking for Photovoltaic-Fed Multi-Source Switched Capacitor Based Multilevel Inverter

摘要

In this paper, a shifting carrier based maximum power point tracking (MPPT) algorithm for multisource converters is proposed. This MPPT algorithm is explained for both low frequency (constant carrier) and high frequency (triangular) carrier signals. The proposed algorithm is applied for a single stage multisource switched capacitor based multilevel inverter for grid connected and stand-alone photovoltaic applications. This converter features high gain, less component count, self capacitor charge balancing, better dispersed value of sources and increased source utilization. The importance of selecting an appropriate pulse width modulation technique for switched capacitor based inverters in order to maintain the capacitor charging time is explained. The proposed technique is able to track the maximum power under varying irradiance levels. The experimental results of the proposed algorithm is presented. The MPPT technique is analyzed and verified in simulation for stand-alone and grid connected applications using MATLAB/Simulink platform.