Investigation on Electromagnetic Vibration Energy Harvesting in Water Distribution Control Valves

Abstract

Control stations of a water distribution system monitor several variables such as the pressure, the flow, and the quality of water. For these monitoring tasks, wireless sensor networks with ultra-low power consumption powered by vibration-based energy harvesters as an alternative to the usage of batteries or wired connections might be a suitable option in these facilities. This article investigates the potential applicability of an electromagnetic vibration energy harvester prototype in different control valves of a water distribution system in the province of Barcelona by means of experimental measurements and numerical simulations. The low-amplitude vibration with random excitation is measured with piezoelectric accelerometers in three control valves under normal operating conditions to process each signal and determine the dominant frequency in the complete spectrum, which is found to be in the order of magnitude of kHz, and the dominant frequency in the range of 10 to 100 Hz, where commercial harvesters normally operate. Numerical simulations of the harvester prototype are conducted in all cases with the same materials, geometries, and coil parameters, generating a maximum RMS load voltage and output power when the harvester's natural frequency matches the dominant frequencies of each vibration signal. The maximum output power estimated in these simulations is 1573.04 nW with a corresponding RMS load voltage of 53.6 mV and optimal load resistance of 1830 Ω.