抄録
Reducing the size of power supplies raises the problem of new elements which could be better candidates to integration. In this field, electromagnetic transformers may be replaced with significant profits by piezoelectric transformers (PT). In a piezoelectric transformer (PT), the input electrical energy is transferred to the output by a mechanical way, using the direct and converse effects of piezoelectric materials. Its main advantages over an electromagnetic transformer are no magnetic noise generation, small size, high power density and high efficiency. This paper presents an innovative non-linear processing technique. This technique is derived from the so-called “synchronized switch damping” technique that was developed to address structural vibration damping problems. Applied to PT, the vibration level of the structure is strongly reduced while keeping the transferred power practically constant. Vibration level is a critical parameter that determines the maximum power capability of a given PT. Thus the new processing reduces significantly losses of the PT for a given power. As a consequence, at vibration amplitude limit, the power capability is drastically enhanced. Theoretical predictions and experimental results both show that the increase of the power capability may reach 450% on a structure similar to a langevin transducer.
