Solar power is a viable energy source for many emerging wearable applications. However, such applications tend to experience varying light intensities over multiple photovoltaic (PV) cells which reduce PV power generation in traditional PV panel and power converter configurations. The concept of differential power processing (DPP) system configuration has been introduced as the key to optimize PV power utilization under nonuniform lighting conditions. Both series and parallel DPP configurations are able to compensate for illuminance mismatch across the PV panels.
This thesis focuses on development of alternative parallel differential power processing approaches and control strategies for low power wearable PV applications. A single-ended primary-inductor converter (SEPIC) and an inverted buck-boost converter were designed and implemented as parallel DPP converters. System efficiency of the DPP SEPIC architecture shows an improvement of 29.3 % compared to the efficiency of the SEPIC alone. Whereas a 27.4 % increase in efficiency was observed with the DPP inverted buck-boost converter architecture in comparison to the efficiency of the converter by itself. When compared to each other, DPP buck-boost converter exhibits a better performance than DPP SEPIC over the full operating range.
In order to balance PV source and load power, a system control strategy that alternates between two modes was implemented; accomplishing both maximum power point tracking (MPPT) and power curtailment when it’s needed. Experimental results verify the control algorithm achieves independent MPPT of each panel and succeeds in maximizing and successfully balancing the power while keeping the maximum temperature of the converter below 37 ℃.

Solar power is a viable energy source for many emerging wearable applications. However, such applications tend to experience varying light intensities over multiple photovoltaic (PV) cells which reduce PV power generation in traditional PV panel and power converter configurations. The concept of differential power processing (DPP) system configuration has been introduced as the key to optimize PV power utilization under nonuniform lighting conditions. Both series and parallel DPP configurations are able to compensate for illuminance mismatch across the PV panels.
This thesis focuses on development of alternative parallel differential power processing approaches and control strategies for low power wearable PV applications. A single-ended primary-inductor converter (SEPIC) and an inverted buck-boost converter were designed and implemented as parallel DPP converters. System efficiency of the DPP SEPIC architecture shows an improvement of 29.3 % compared to the efficiency of the SEPIC alone. Whereas a 27.4 % increase in efficiency was observed with the DPP inverted buck-boost converter architecture in comparison to the efficiency of the converter by itself. When compared to each other, DPP buck-boost converter exhibits a better performance than DPP SEPIC over the full operating range.
In order to balance PV source and load power, a system control strategy that alternates between two modes was implemented; accomplishing both maximum power point tracking (MPPT) and power curtailment when it’s needed. Experimental results verify the control algorithm achieves independent MPPT of each panel and succeeds in maximizing and successfully balancing the power while keeping the maximum temperature of the converter below 37 ℃.

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