基于多个压电换能器的接口电路

为了探究多压电换能器并联时的能量输出特性,以标准电路和同步电感电路(SSHI)为基础提出4种多压电换能器并联电路,对4种电路下的输出功率进行理论推导,并探讨激振力之间相位差对并联输出功率的影响.结果表明：如果多压电换能器采用先并联后整流的标准/SSHI电路,激振力之间相位差对输出功率有影响,并且最终的并联输出功率由相位差、激振频率及接口电路共同决定.如果多压电换能器采用先整流后并联的标准/SSHI电路,激振力之间相位差对并联输出功率没有影响,输出功率由激振频率和接口电路决定.对比4种接口电路,采用先整流后并联的SSHI接口电,输出功率峰值较高、带宽较宽,在4种电路中综合效果更好.

Research on interface circuits of multiple piezoelectric generators

To explore the output power performance of multiple piezoelectric generators which are connected in parallel mode and work cooperatively, four kinds of parallel-connection interface circuits for multiple piezoelectric generators were proposed based on the standard circuit and the synchronized switch harvesting on inductor (SSHI) circuit. The output power in these four kinds of interface circuits was theoretically derived and the influence on it by the phase difference among the exciting forces was studied. The results show that for piezoelectric generators connected in parallel mode, if the piezoelectric generators are rectified after parallel connection and link with standard/ SSHI circuit, the phase difference between exciting forces has effect on the output power, and the output power is decided by the phase difference,the interface circuit and the excitation frequency. If piezoelectric generators are connected in parallel after rectifier bridges and link with standard/SSHI circuit, the phase difference has no effect on the output power and in this situation, the output power is decided by both the interface circuit and the excitation frequency. Compared among the four kinds of interface circuits, a system consists of multiple piezoelectric generators which are connected in parallel after rectifier bridges and link with SSHI circuit has higher output power and wider frequency bandwidth, so its comprehensive results are more acceptable．