The new topology of dual-bridge isolated piezoelectric resonator converter (DB-IPRC) provides isolation using two independent piezoelectric resonators. This improved version of a DC-DC converter significantly improves efficiency, while at the same time maintaining the converter isolation principle.
The results of this work were reported in a paper, “Switching Assisting Circuit Improving the Efficiency of DC-DC Converters Based on Piezoelectric Resonators”, which was presented at PCIM Europe 2024.
The paper notes that “for a 200 V to 120 V conversion, the converter shows an efficiency of 96.2 percent with the inductive assisting circuit, 94.3 percent with the piezoelectric one and 87.4 percent without any assisting circuit. The (piezoelectric resonator) assisting circuit offers a gain in efficiency over a smaller operating range than the inductance but leads to a flatter converter.”
The work expands on previous results that were reported by CEA-Leti in the August 2023 issue of “IEEE Transactions on Power Electronics” in an article that said the new topology “uses the natural isolation of piezoelectric resonators to isolate the converter’s output from the input and vice-versa.”
The use of piezoelectric resonators instead of inductors in power conversion “will lead to a dramatic reduction in the size of power converters,” explained Ghislain Despesse, a co-author of the PCIM paper and the earlier article. “Our results make it possible to extend this type of compact conversion to isolated converters. So, this type of converter is now compatible with a much wider range of applications, such as TVs, phones, tablets and electrical tools.”
“For many people, piezoelectricity is associated with energy harvesting and the idea of low power,” explained Despesse. “But in power conversion, piezoelectrics operate at high frequencies, greater than 100kHz, with no limits in terms of input power. That makes it possible to reach power levels of several hundred watts. The range of applications is therefore very broad, with most converters having a rated power of less than 100W.”
