Summary: | 博士 === 國立臺灣大學 === 生物產業機電工程學研究所 === 104 === To facilitate the efficiency of the MPPT algorithm, we have developed the new, simple, and direct-prediction method with a low calculation burden in this study. These proposed methods were developed based on the p-n junction semiconductor theory of solar cells. We develop a new single-phase two-stage PV inverter, where the input current sensors for tracking the MPP are not required. A new hybrid maximum power point tracking (MPPT) algorithm was developed to speedily achieve the MPP tracking of the PV arrays. A grid-tied PV power conditioning (PVPC) system with a capacity rating of 4 kW was constructed as a test sample system. The energy harvesting performance by using the hybrid MPPT method and the conventional perturbation and observation (P&O) method was also compared, and the test results show that the new designed PV inverter could produce 2.72% more energy than the traditional one. In this paper, we define an energy harvesting enhancement index (EHE-index) to Energy harvesting performance comparison of different commercial PV inverters equipped with various MPPT methods. The hybrid MPPT method is also good in speed, stable and efficiency in energy performance. The inverter developed in this study is pretty promising in energy production of PV systems and is ready for commercial use in the future.
Furthermore, we integrate the previously proposed direct-prediction MPP method with the perturbation and observation (P&O) method to develop a new hybrid MPPT method. The proposed MPPT method was further utilized in the PV inverters in a PV system installed on the roof of a closed plant factory at National Taiwan University. Based on experimental results obtained from an outdoor environment over one year, the hybrid MPPT method not only decreases energy loss but also increases power utilization for the PV system. These results feature the role of applying the PV system to the closed plant factory for saving energy consumption and reducing CO2 emission.
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