Multivariable Newton-Based Extremum Seeking Control for 13.56 MHz RF Impedance Matcher

Fast and accurate impedance-matching control is essential to maximize power transfer from the 13.56 MHz power supply to the plasma load. This article introduces a feedforward compensation combined multivariable Newton-based extremum seeking control (FC-MNESC) for impedance matcher. An inverse Hessian matrix estimator is designed to eliminate the reliance on initial conditions and the Hessian of the cost function. As a result, the disturbance immunity is enhanced and the convergence time can be adjusted freely. In addition, a feedforward compensator is established, further reducing the matching time. Stability analysis of the FC-MNESC is carried out by average theory. Experimental results verify the effectiveness of the FC-MNESC.