Modeling and Stability Analysis of LCL filtered VSCs in Interleaved Topology

Abstract:
As the integration of renewable energy resources into the European power grid accelerates, high-power grid-connected Voltage Source Converters (VSCs) are becoming increasingly pivotal. This paper delves into the modeling of interleaved VSCs and analyzes two different control schemes, utilizing converter-current and grid-current feedback methodology. Through the application of the Nyquist Stability Criterion (NSC), the stability of the two control schemes is analyzed, identifying the critical frequency essential for system stability. Performance validation of the two control schemes is presented using an experimental testrig.