Subharmonic driving: a new concept to drive piezoelectric transformers in power converters

A new concept to drive piezoelectric transformers (PT) is presented and validated in this paper. The subharmonic driving consists on applying a voltage waveform to the PT whose fundamental frequency (f/sub PT//n) contains the resonance harmonic (f/sub PT/) at which the PT transfers the energy. It is important to highlight that this solution is proposed in order to improve the whole power converter, even if the PT performance is not as good as it could be with sinusoidal excitation. The PT should be specifically designed to handle more energy.