A study of harvested power and energy harvesting efficiency using frequency response analyses of power variables

摘要

Frequency response analysis of field variables such as force, displacement/velocity, voltage was conducted in the previous work to study harvesting vibration energy under the base excitation of the random and sinusoidal signals. This paper proposes a unique method for conducting frequency response analysis on power variables under a new unified theoretical framework to determine the time averaged harvested power or energy harvesting efficiency under the excitation of the random and sinusoidal signals. The uniqueness of the method is to directly measure and calculate the time averaged output power and efficiency for piezoelectric and electromagnetic vibration energy harvesters under different excitations regardless of the dimensions or sizes of the vibration energy harvesters. This paper has studied the frequency responses of power variables and their mean/dc values and illustrated the relationships of the mean/dc values with the mean harvested power or energy harvesting efficiency.