An Adaptive Energy Management Strategy to Extend Battery Lifetime of Solar Powered Wireless Sensor Nodes

Traditional energy management strategies of wireless sensor network (WSN) nodes with hybrid energy storage do not adequately combine the merits of supercapacitors (SCs) and batteries, and thus, battery degradation remains a problem that restricts the lifetime of the WSN nodes. In this paper, an adaptive rule-based energy management strategy is proposed to extend the battery lifetime of a solar-powered wireless sensor node. The energy models are constructed with the consideration of the battery degradation, and Poisson distribution is utilized to simulate the power consumption variation of the node. A rule-based energy management strategy that is adaptive with the SC capacity and load conditions is designed. Traditional energy management strategies of the WSN nodes are compared with the proposed one. The simulation results indicate that the proposed strategy can improve the node lifetime from several tens of days to more than ten years. Meanwhile, the strategy ensures the continuous availability of the solar-powered WSN nodes even at night throughout the long lifetime. The robustness of the strategy is also tested. It is revealed that the strategy is adaptive with the SC capacity and workload conditions. The proposed strategy is broadly applicable and promising to resolve the problem of limited battery lifetime for the solar-powered WSN nodes.