Stochastic dynamics of a tri-stable piezoelectric vibration energy harvester interfaced with a standard rectifier circuit

• A coupled tri-stable energy harvester under colored noise is considered. • A standard rectifier circuit is chosen as the harvesting circuit for DC supply. • The improved stochastic average is developed to obtain the theoretical solution. • The stochastic dynamics of the coupled system are studied to enhance DC delivery. • The effect of parameters on harvesting performance is explored to optimize design. • Simulation and experiment verify the effectiveness of the theoretical method. In this paper, the nonlinear dynamics of the tri-stable piezoelectric vibration energy harvester (TPVEH) interfaced with a standard rectifier circuit under colored noise is investigated. A full-wave rectifier bridge is used to convert the harvested alternating current (AC) into a direct current (DC) for external electronic equipments. Considering the segmental non-smoothness of the piezoelectric voltage caused by the rectifier circuit, the fundamental harmonic component is used as an approximate substitute. Then, the equivalent uncoupled system and joint probability density function (JPDF) are obtained by using the improved energy envelope stochastic average method. The effects of colored noise and system parameters on dynamical behaviors and harvesting performance are further discussed. The mean output rectified voltage and power conversion efficiency achieve the maximum for a symmetric tri-stable potential, which can be achieved by adjusting the electromechanical coupling coefficient. The time constant ratio is conducive to improve the mean harvested power and power conversion efficiency of TPVEH, but it can also weaken the rectification efficiency of the harvesting circuit. Thus, the appropriate designs of electromechanical coupling coefficient and time constant ratio play an important role on the harvesting performance. Moreover, the noise intensity can induce the random transitions and increases the average harvested power. Finally, the theoretical results are well verified through the numerical simulations and experimental verification.