Optimised conversion for a low-voltage low-power energy harvesting powered sensor

The aim of this paper is to examine existing DC-DC conversion techniques for a low-power low-voltage energy harvesting powered wireless sensor and propose an optimum conversion solution that will increase the overall efficiency. Several state-of-the art converters that have been developed for a low-voltage source powered wireless sensor load are investigated. The most efficient existing solution for a typical EH source, i.e. indoor solar cell, powering a wireless sensor has been found to be a boost converter. This conversion technique is examined in detail and methods to enhance the operation for wireless sensors are proposed. This is achieved by introducing an additional switched capacitor circuit which optimizes the conversion step for a wireless sensor load. An initial investigation has shown an increase in efficiency of up to 10% when compared with a boost converter only solution.