井下随钻星型压电振动俘能结构输出特性OA

To address the power supply issue of downhole sensors,a multi-beam star-shaped piezoelectric vibration energy harvesting structure for logging while drilling(LWD-PVEH)was designed,and the dynamic equation of a single-beam piezo-electric vibrator in the LWD-PVEH was established.An experimental setup for the single-beam piezoelectric energy harves-ting structure was constructed,and energy harvesting experiments were conducted to analyze the open-circuit voltage output characteristics of the piezoelectric vibrator.The feasibility and effectiveness of LWD-PVEH were verified.To investigate the influence of LWD-PVEH parameters on electromechanical conversion performance,a coupled dynamic model of the LWD-PVEH was developed using the simulation software COMSOL multi-physics.The modal characteristics of the LWD-PVEH were firstly analyzed through simulations,followed by studies on the effects of excitation frequency,beam structure dimen-sions,and vibration direction on the power generation capacity of LWD-PVEH.The results indicate that when the excitation frequency is close to the lower natural frequency of LWD-PVEH,the power generation capacity of the device is significantly enhanced.The energy harvesting efficiency reaches its peak when the length ratio of the short beam to the long beam is 0.65 and the beam angle is 45°,while also maintaining a high energy density.The LWD-PVEH structure is more effective at cap-turing axial vibration energy from the drill string,and its performance in harvesting lateral vibration energy can be improved by optimizing the design or orientation of the beams.