Three-Level Interleaved Boost Converter with Irradiance Adaptive Controller for Solar Power Utilization

Abstract

Solar energy conversion through photovoltaic is a rapidly growing source of green power supply. Therefore, improving the efficiency of PV system is considered as an important factor in supporting this trend. However, this concerns not only the improvement of PV cells, but also the efficiency of the power electronics circuits and the controls associated with them. Also, the PV modules are operated at low voltage levels, therefore, large voltage boosting is essential for various solar power application. Hence, a PV module integrated converter suitable for boosting voltage is designed and simulated. Switching Frequency Modulation (SFM) is also proposed which selects an irradiance adapted switching frequency that is always high enough to avoid operation in discontinuous conduction mode. Furthermore, an interleaved boost cell is activated at high irradiance to retain high level of power quality. Therefore, by combining SFM with the adaptive usage of interleaved boost converter cells and a fast MPPT, the targets of efficiency and power quality are attained. Keywords: discontinuous mode of conduction (DCM), interleaved boost converter (IBC), module integrated converter (MIC), photovoltaic (PV), switching frequency modulation (SFM)