Abstract
In the conventional photovoltaic (PV) fed quasi-Z (qZ) network-based impedance-source converters (ISCs), the PV array is connected to their input, whereas in the proposed topology in this article, an additional array is paralleled to the second qZ-network's capacitor (C 2). This modification allows harvesting more PV power through full utilization of the employed qZ-network in the classical ISCs. Moreover, the proposal offers higher conversion efficiency since the current in the second qZ-network's inductor (i_L2) is smaller. The voltage of the added PV array (PV 2) is independent of the voltage of the primary array (PV 1) in a wide range, which promotes tracking their maximum power points (MPPs) separatly, achieving a higher efficiency even under partial shading. The use of two separate maximum power point trackings (MPPTs) in one converter is a challenge since the perturbation done by the first MPPT alters the power in PV 2 as well, and vice versa. Therefore, a two MPPs tracker algorithm, which perturbs two parameters and observes four variables, is proposed for the presented converter. The theoretical analysis is validated through real-time hardware-in-the-loop tests, and it demonstrates that at least 11% more power can be harvested compared to the conventional qZ-network-based ISC.
Original language | English |
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Article number | 8818616 |
Journal | I E E E Transactions on Industrial Electronics |
Volume | 67 |
Issue number | 8 |
Pages (from-to) | 6483-6493 |
Number of pages | 11 |
ISSN | 0278-0046 |
DOIs | |
Publication status | Published - 2020 |
Keywords
- Efficiency
- Photovoltaic power systems
- MPPT
- Power grid
- Impedance source converter
- photovoltaic (PV) power systems
- maximum power point tracking (MPPT)