Direct cloud-enabled sensor nodes offers certain advantages over low-power wireless communication technologies but require high-power. Conventional wireless sensor nodes, which are battery-powered, have relatively low lifespan. In a battery powered direct cloud-enabled sensor nodes, the peak current needed during the data transmission process will add extra burden on the already strained battery resources and may accelerate the capacity degradation, further reducing battery life. The condition deteriorates where applications require frequent data transmission. This paper proposes a novel power management device architecture tailored to direct cloud-enabled sensor nodes’ requirements for indoor applications with extended lifespan. This research also recommends using Photovoltaic energy harvesting with a hybrid storage technique consisting of a battery and supercapacitor to power the node. The work’s novelty lies in the use of a supercapacitor-battery hybrid storage scheme, which provides the required peak current during the data transmission, sufficient enough to fulfill the load requirement during the data transmission process. A novel drip charge controller synchronized with the sleep period, and the active period of the sensor node is introduced. The power management unit was designed simulated and validated experimentally to verify performance with the indoor application.
Keywords Battery-Supercapacitor hybrid storage, Indoor PV Energy harvesting, Power management unit, Direct cloud-enabled device, Wireless sensor network