Optimum energy harvesting among distributed power sources with uniform voltage distribution

This paper presents two power system architectures where distributed-input parallel-output (DIPO) DC-DC converters are controlled to achieve their equal input voltages while harvesting electricity from their distributed power sources at a system optimum power point; the system optimum power point is the maximum power drawn from the distributed power sources while their voltages are kept uniformly distributed^{1 2} even though their individual peak powers are different. With proper uniform input voltage distribution control, near maximum use of the power sources is achieved by employing only one maximum power tracking (MPT) controller instead of multiple MPT controllers dedicated for their respective power sources. Provided that the maximum power point voltages of the input power sources are similar, the resulting system and control architectures offer near-maximum power transfer with a lower parts count. The two DIPO power converter architectures are also described in detail: one with the battery-dominated output voltage bus and the other with the regulated output voltage bus. A feasibility study using computer simulation has successfully validated both power architectures and their control concepts for optimum energy harvesting and maximal fault-tolerances for failures of more than one power source or converter.