Stability and Performance Analysis in Two-Parameter Controllers for Weak Grid-Connected VSCs

Abstract

In this study, we conduct an analysis of power control in a Voltage Source Converter (VSC) connected to a Weak Grid (WG), focusing on the system's stability and performance. Our main objective is to predict the behaviour of the VSC under different conditions. To address this analysis and enhance the control capabilities, we propose a two-parameter control structure and we develop a controller design methodology that ensures specific criteria are met, such as maintaining maximum voltage deviations at the Point of Common Coupling (PCC), achieving a minimum acceptable Short Circuit Ratio (SCR), and attaining the desired time response. Additionally, we establish criteria to avoid problems associated with grid synchronization using a Phase-Locked Loop (PLL). Finally, through representative simulations, we validate the accuracy of our predictions regarding the system's behaviour. Furthermore, the proposed design procedure proves to be highly effective in achieving the desired outcomes. This study contributes to the understanding of power control in VSCs connected to Weak Grids, providing valuable insights for designing robust and high-performing systems in such scenarios.