Abstract
This paper introduces an iterative method for controller tuning that adjusts parameters based on the global influence on all eigenvalues, weighted by their importance on the system behavior. The approach addresses a key limitation of existing sensitivity-based tuning algorithms, which typically prioritize only one critical eigenvalue and may overlook important multi-mode interactions. In the proposed method, the real part of the parametric sensitivity is weighted with the real part of the eigenvalue and the corresponding Hankel Singular Value (HSV). Then, a parameter sensitivity index is calculated by summing the weighted sensitivity of all eigenvalues. The parameter that produces the largest total weighted improvement of eigenvalue locations is updated by a fixed positive/negative increment in each iteration, enabling coordinated tuning of parameters influencing multiple modes. The method is demonstrated on a grid-forming power converter controlled as a Virtual Synchronous Machine (VSM) with cascaded voltage and current control loops, achieving faster response and more consistent damping compared to tuning based on the sensitivity with respect to a single mode.