Energy conversion and performance of switched-voltage control based on negative capacitance with arbitrary switching frequency

Abstract

In semi-active synchronized switch damping (SSD) approaches for structural vibration control, the damping effect is achieved by properly switching the voltage on the piezoelectric actuators. In this study, the energy conversion of a synchronized switch damping system based on negative capacitance (SSDNC) with an arbitrary switching frequency is investigated theoretically and validated numerically. First, the model of a general SSDNC system with an arbitrary switching frequency is presented. The general expression of the switched voltage on the piezoelectric actuator is derived. Next, the average converted energy per vibration cycle was derived for arbitrary switching frequency. The results show that the efficiency of energy conversion is reduced by about one half even if the switching frequency deviates slightly from the optimal frequency, which is similar to the SSDI control system. However, the control performance of SSDNC is better than that of SSDI for most non-optimal switching frequencies. Finally, the general expression of control performance of a SSDNC control system for a specific mode is derived and a numerical example is given to support the theoretical results.