The application of piezoelectric elements in power electronics

Piezoelectric materials, which perform direct electromechanical conversion, have been used for many years in power applications such as ultrasonic generation and actuation. The field of use of these materials continues to grow in power electronics, notably with piezoelectric transformers and microenergy sources.

The piezoelectric transformer has found a commercial outlet in cold-cathode lamp power supplies for LCD backlighting, thanks to its voltage-boosting performance.

Piezoelectric microgenerators whose energy is derived from ambient vibration have a promising future in applications such as the self-powering of abandoned sensor arrays, thanks to good electromechanical conversion performance and compatibility with microsystem manufacturing technologies.

The aim of this dossier is to present the potential, but also the constraints, generated by the use of piezoelectric materials in various power electronics applications with :

• An introduction to piezoelectric materials and a classification of conversion modes (§ 1 );

  energy recovery systems (§ 2 );

  power supply for ultrasonic power generators and actuators (§ 3