A GaN Devices Based Resonant Soft-Switching Power Converter for Electrosurgery Applications

Electrosurgical generators (ESGs) are medical power devices that utilize the thermal effects of high-frequency current flowing through human tissues. However, the surgical process involves a wide range of tissue variations. This means that the ESG needs to provide a large range of output voltages to ensure constant power output during load changes. This paper introduces the topology of a resonant soft-switching power converter. The design achieves power closed-loop control through pulse-frequency modulation, adjusting the switching frequency to achieve a wide range of output voltage regulation to meet the requirements of load changes. To verify the practicality of this method, an experimental platform with a fundamental frequency of 500kHz and an output power of 300W was built. Moreover, GaN power switching devices were used, achieving lower conduction losses and being more suitable for high-frequency application scenarios. In the experiment, a variety of clinical output modes involved in the application of the electrosurgical unit were covered, and it was proven that the topology has a fast response speed.