Evaluating the performance of a vibration energy harvester under complex excitation

Abstract: In recent years, vibration energy harvesting has become a research hotspot in the field of energy harvesting. Energy harvester output power is the most important parameter in a vibration energy harvesting system. Assessing the harvester output power in different vibration environments is an important study issue to study. This thesis proposed a research method for harvester output based on the complex vibration environment simulated in the laboratory, a closed-loop control experimental system for the simulated vibration environment was established, the system can simulate a vibration environment with specific vibration frequency and acceleration, and automatically measure the harvester output power. Using FFT methods to analyse the harvester output voltage waveform, research the relationship between the harvester output power and the noise vibration signal frequency. Polynomial fitting modelling method is used for the harvester output power prediction in the 62.5Hz dominant frequency vibration environment. At the same time, researching the harvester output power in different dominant frequency and same vibration acceleration vibration environment which containing noise signal. Through the analysis of harvester output power, it was found that, for the case of the vibration environment dominant frequency is 62.5Hz, all noise frequency component of the vibration signal will reduce the output power of vibration energy harvester modelD, especially when the noise frequency is around 57.5Hz and67.5Hz, the output power of vibration energy harvester modelD is quite lower than the output power of harvester under the pure sinusoidal excitation signals. For the case of the vibration environment dominant frequency is not 62.5Hz, if the noise frequency component of the vibration signal close the harvester resonance frequency, it has a great impact on output power, and the output power of harvester is higher than the output power of harvester under the pure sinusoidal excitation signals. The presented research methods apply to most such studies, which can help user to analyse the effect of vibration noise on the harvester output and helps increase the harvester's output power. Research conclusions can provide user a reference in harvester selection.