On the Stabilizing Contribution of Different Grid-Forming Controls to Power Systems

Abstract

The increasing penetration of power-electronics interfaced resources brings new challenges regarding the small-signal stability of power systems. To address this issue, grid-forming controlled converters have emerged as an alternative to their conventional grid-following counterparts. This paper investigates the mechanisms behind converters driven stability and quantifies the stabilizing effect of grid-forming controls. The linearized state space model of different combinations of control strategies is analyzed in a multi-infeed system considering various operating points. Through a parametric sensitivity study and an examination of the participation factors of key eigenvalues of the linearized models, it is confirmed that grid-forming controls contribute to system stabilization. Moreover, this paper demonstrates that this stabilizing effect varies significantly depending on the specific grid-forming control implemented: whether a current control loop is used or not, notably impacts stability.