Large signal measurements on piezoelectric stacks

Abstract

The knowledge of the dielectric large signal properties of piezoelectric actuators for dynamic use is necessary to estimate the limits of application, to optimize the driving electronics, and to improve the actuator materials. A measurement technique has been developed for determination of the large signal parameters capacity, loss tangent, loss power, and dilatation in dependence on the control voltage amplitude, frequency, temperature, and bias field strength and first experimental results are presented. The effective capacitance, which has been measured with large control amplitudes, determined the output parameters of the control electronic and the stability of the set up. The loss power (loss tangent) influences the heating of the piezo-actuator when large control amplitudes and high frequencies are used. The comprehensive data files from the set-up include many additional information which can be evaluated by a comfortable evaluation software. A loss power hyperbola of pie-actuators is derived being analogous to the loss power hyperbola of transistors. In addition, aging effects were investigated for the effective capacity, the loss power and the dilatation after a complete temperature and electrically field cycle. Harmonic distortion of the actuator current by controlling with large amplitudes and the change of the loss power by controlling with saw tooth and rectangular control voltages have bee measured.

Hysteresis independent on-line capacitance measurement for piezoelectric stack actuators

“…However, figure 6 shows little dependence between the capacitance measurement and the hysteresis of the driving voltage. This is attributed to the fact that hysteresis is a large signal phenomenon that is not usually observed at small signal values [6]. This can be validated by zooming into the voltage current plot of the ripple signal, which displays a linear elliptical shape without hysteresis in figure 8.…”

“…Previous studies [6,7,8] show that the capacitance value is dependent on different factors such as applied electric field, actuator temperature, and aging. So the assumption of a constant capacitance value in the model is not a realistic approximation while the actuator is operated in highly dynamic applications.…”

“…A third approach uses a bridge circuit with a known reference impedance in order to obtain an effective capacitance for the piezoelectric actuator by comparing the transfer function of input and output voltage to the bridge circuit [6].…”

Investigation of large signal properties of quasi-static lead zirconate titanate actuators at elevated temperature

“…Over the years, quasi-static piezoelectric actuators, in particular multilayer actuators, have gained maturity, finding numerous applications, for example, in aerospace applications. However, although some literature is available on large signal stress-strain behaviour, 1-4 in many cases, the designer still misses essential parameters for describing the behaviour of these actuators, in particular for high-temperature applications. The present work is performed within the project AeroPZT, specifically funded under the Clean Sky Joint Technology Initiative (EU FP7).…”

Investigation of Elevated Temperature Effects on Multiple Layer Piezoelectric Ultrasonic Transducers with Adhesive Bondlines by Self-Heating

“…These structures are free of adhesive bondlines subjected to tensile stress because adhesive bonds have low thermal conductivity, low Q m value, and low www.intechopen.com Investigation of elevated temperature effects on multiple layer piezoelectric ultrasonic transducers with adhesive bondlines by self-heating 25 maximum operating temperature. Different aspects such as loss effect, temperature rise, and self-heating mechanisms of piezoelectric devices have been studied on this topic, both on practical experiments (Robertson & Cochran, 2002;Dubus et al, 2002;Wehrsdorfer et al, 1995;Zheng et al, 1996) and theoretical analyses (Wang et al, 1996;Flint et al, 1995;Ye & Sun, 1997). Heat generation in various types of multilayer PZT-based actuators was reported in 1996 and a simplified analytic method to evaluate the temperature rise was also developed (Zheng et al, 1996).…”