Analysis of Piezoelectric Energy Harvesting Interface Circuit Applied to Automobile Engine Vibration

In order to realize the continuous power supply for the vibration fault monitoring system of automobile engine, aiming at the low efficiency and instability of the existing piezoelectric full bridge rectifier energy collection circuit, this paper proposes a circuit scheme based on synchronous charge extraction. The scheme can provide circuit collection efficiency, and analyze the power of the circuit by impedance analysis. Finally, the experiment shows that the theoretical analysis is consistent with the experimental results. And the synchronous electrical charge extraction circuit can harvest power up to 1.3mW under low frequency conditions, which is higher than 0.5mW collected by the full-bridge rectifier circuit under the same conditions. The harvested energy meets the power requirements of automotive sensors and microcontrollers.