Comparison of BSPT and PZT piezoelectric ceramic transformers for high temperature power supplies

High temperature power electronics is an advancing area of research, especially given the widespread availability of wide bandgap semiconductors. In this work a suitability analysis of (1−x)BiScO3–xPbTiO3 (BSPT) as a material for high temperature piezoelectric transformers (PTs) is presented and compared to state-of-the-art Pb(Zr1−xTix)O3 (PZT). Initially, both materials will be compared using a variety of metrics to prove the suitability of BSPT as a material for constructing PTs specifically for high temperature applications. PTs based on the two materials are designed and fabricated, and then subsequently characterised using impedance measurements. Finally, half-bridge resonant inverters are constructed using both PTs and the performance of each inverter measured over a range of ambient temperatures. The result of these experiments confirm the suitability of BSPT for PT applications and show the excellent performance of BSPT PTs at temperatures in excess of that possible with PZT based PTs.