Optimal battery control strategy for wireless sensor networks with solar energy supply

Battery energy management and optimization are of significant importance to self-sustained wireless sensor networks (WSNs) that use solar energy harvesting instead of fixed power supply as the charging source. In this paper, an optimal control strategy for WSNs with solar energy supply is proposed. A modified Kinetic Battery Model (KBM) considering charging input is introduced to account for the dynamic characteristics of a rechargeable battery. To fully utilize available solar energy during each sampling cycle of the WSNs, dynamic voltage scheduling (DVS) is incorporated to flexibly adjust the working period of flexible tasks. The length of working periods is decided based on the derived optimal solution. Numerical simulation is carried out to evaluate the proposed optimal control strategy. The result indicates significant energy saving as compared to the conventional battery control strategy.