Assessing Stability and Predicting Power Generation of Electromagnetic Vibration Energy Harvesters Using Bridge Vibration Data

This paper presents the use of the power harvesting ratio (PHR) approach for evaluating the power harvesting capabilities of an electromagnetic vibration energy harvester. This is done for different electrical loads and measured bridge vibration data displaying multiple frequency components. Bridge vibration data are collected and characterized. The modes of the bridge are determined using a model sledge hammer, and the response of the bridge to a single vehicle is measured. Analysis of the data reveals that several of the modes contribute toward a response with multiple non-negligible frequency components. Measured bridge time-series data are then replayed on an experimental setup with an electromagnetic vibration energy harvester. Six electrical loads are implemented on the experimental platform: four passive loads and two active loads. The PHR approach is used to predict the average power from each load. Experimentally measured average power is within 6% of the predicted average power. The PHR approach is also used to successfully predict harvester instability for the active load dictated by the maximum power transfer theorem and validated experimentally. This paper demonstrates the utility of the PHR approach in evaluating harvester stability and performance for multifrequency excitations and sophisticated electrical loads, including active loads.