Impact Analysis of the Distribution and Installation Proportions of Grid-Forming and Grid-Following Converters on the Stability of a 100% Renewable Energy System

Nowadays, China and Europe have planned and built 100<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">%</sup> renewable energy systems (RESs) with grid-following (GFL) and grid-forming (GFM) converters. One of the significant issues for developing a 100% RES is how to design the distribution and installation proportions of GFL and GFM converters for a better stability performance. This paper proposes a method to analyze the impact of distribution and installation proportions of GFL and GFM converters on the small-signal stability of a 100<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">%</sup> RES. A unified model of a 100% RES with different distribution and installation proportions of GFL and GFM converters is presented to describe the dynamic characteristics of the system. Then, equipped with the maximum singular value, we propose a stability indicator to assess the stability margin of a 100% RES, which is a typical multiple-input multiple-output (MIMO) system. Simulations verify the validity of the proposed method and the analysis results.