Efficient power amplifiers for piezoelectric applications

The principal obstacle to greater utilization of piezoelectric actuators in aerospace applications is the extreme inefficiency and heat rejection requirements of the driving electronics. The purpose of this investigation is to take a critical look at how amplifiers for piezoelectric systems are designed and to look for potential areas for improvement. A dimensional analysis of a piezoelectric actuator is performed that indicates that power consumption in an unloaded actuator is extremely low, placing the blame for the exorbitant power demands squarely on the driving electronics. Several strategies for power savings in piezoelectric driving electronics are presented including pulse width modulation, discrete charge control, and a hybrid charge-recovery strategy.