Experimental variable band hybrid current mode control for high power high frequency inverter in electro surgical applications

Abstract

Electrosurgical generators (ESGs) are vital during medical operations, providing high-frequency electrical currents for cutting tissue and coagulation in surgery. Maintaining precise control over output power is challenging due to variable tissue loads. Inconsistent regulation can lead to undesirable surgical outcomes. This paper addresses this challenge through a novel Variable band hybrid current mode control (VBHCMC) technique. The study explores the limitations of existing approaches, such as peak current mode control (PCMC), emphasizing the need for improving control methodologies. The proposed VBHCMC method ensures stable output power, addressing issues associated with PCMC. It dynamically adapts the hysteresis band for variable load impedances, enhancing stability. The significance of this approach lies in its ability to combine the benefits of peak and valley current mode controls while maintaining a nearly constant switching frequency, significantly reducing steady-state errors. Results demonstrate significant reduction in steady-state errors compared to conventional PCMC. The proposed controller provides an effective solution to challenges faced in regulating output power during surgical procedures, enhancing safety and precision. The results have been verified in the MATLAB/Simulink environment, Processor-in-Loop (PIL) simulation in PSIM and using hardware validation.