Analysis of energy conversion in switched-voltage control with arbitrary switching frequency

In a structural system with piezoelectric actuators, the damping effect can be achieved by properly switching the voltage on the actuators. Semi-active synchronized switch damping (SSD) approaches are typical switched-voltage control methods, which have recently been a topic of active research. In this study, the energy conversion of a SSD control system with an arbitrary switching frequency is investigated theoretically and validated numerically. First the general expression of the switched voltage on the piezoelectric actuator is derived. The results show that maximum voltage magnitude is obtained on the piezoelectric actuator when piezoelectric is switched at every odd number of displacement extrema. Next the average converted energy per vibration cycle is derived for an arbitrary switching frequency. The results show that the efficiency of energy conversion is reduced drastically even if the switching frequency is slightly deviated from the optimal frequency. Finally numerical simulation and experiments were carried out to validate the theoretical results.