| Popis: |
Photovoltaic (PV) energy harvesting suffers from output energy reduction due to shading, dirt accumulation or manufacturing variability. Typical PV modules consist of 60 solar cells connected in series. Hence, shading a single cell can cause a whole substring of 20 cells to be bypassed. To overcome these drawbacks, this paper proposes the application of boost converters on submodular level, cutting the series connection to only a few cells. System level simulations prove that this architecture features increased output energy compared to state-of-the-art approaches like power optimizers. For reducing component costs and increasing system reliability, an ASIC for this application has been developed in a 150nm CMOS technology. This paper describes the design and the implementation of a highly efficient hysteretic controlled boost converter. Its high switching frequency of more than 500 kHz enables operation on a single phase while achieving an RMS input current ripple of less than 1.5 % required in photovoltaic applications. Measurements prove a RMS current ripple of less than 1 % and a maximum switching frequnecy of 650 kHz. |
