Methods to Enhance the Energy Supply of Photovoltaic System for Solar-Powered Unmanned Aerial Vehicle

Abstract

This article proposes a cyclic shift (CS) reconfiguration scheme and a two-stage maximum power point tracking (TS-MPPT) method to enhance the energy supply of solar-powered unmanned aerial vehicle (SPUAV) photovoltaic (PV) systems under partial shading conditions (PSCs). The proposed CS reconfiguration scheme disperses shadows by moving PV modules longitudinally and deduces the optimal movement distance. This scheme not only improves power delivery during PSCs but also simplifies the maximum power point tracking (MPPT) method by aligning the global maximum power point (GMPP) with the right power point (RPP). Furthermore, the proposed TS-MPPT method takes the derivative of the P–V curve to position the maximum power point (MPP) on the x-axis, and the MPP is tracked by solving the intersection points of the linear equation. The proposed method significantly reduces the tracking time and eliminates the drift phenomenon. The proposed reconfiguration scheme and the control method are simulated and experimentally verified under various PSCs. Results indicate that, compared to the total-cross-tied (TCT) scheme, the CS reconfiguration scheme enhances PV energy output by 25.65%. Compared to the perturb and observe (P&O) method, the TS-MPPT method reduced the start-up time and tracking time by 60.6% and 39.1%, respectively.