Design and Performance Evaluation of PID Controllers for a Buck Converter for Electrosurgical Units

Electrosurgery is a systematic process within different surgical procedures; this technique introduces a high frequency and power signal into the biological tissue to fulfil a specific surgical procedure. Then, the electronic device used by the surgeon must guarantee the desired high frequency, current and voltage for the process. However, the tissue bioimpedance changes due to many factors, such as its anisotropic properties, hydration, and the applied current frequency. Therefore, the electrosurgical unit (ESU) design is based on electronic circuits capable of efficiently compensating for the load changes. This contribution describes a closed-loop scheme for power control based on a classical PID control. The article presents the performance of the PID controller in the face of changes in load.