Modeling and Stability Issues of Voltage-source Converter-dominated Power Systems: A Review

Abstract

With the substantive increase in the proportion of voltage-source converter (VSC)-based equipment, traditional power systems that primarily constituted of synchronous generators (SGs) gradually evolved into VSC-dominated ones. At the same time, there is an urgent need for modeling and stability assessment of such systems, since low inertia and weak damping features impair the ability of the systems to resist random disturbances. Existing works model the system dynamic processes from various domains (i.e., time, frequency and energy), and analyze/determine the system stability under small or large disturbances. Among them, small-signal stability assessments mainly adopt the time-domain analysis based on the state-space model while frequency-domain methods include the impedance model, phase-amplitude dynamics model, and static synchronous generator model. Large-signal stability assessments mainly exploit the time-domain simulation with detailed models (i.e., continuous/discrete-time mixed model with differential-difference-algebraic equations), and the energy-domain analysis is based on energy function models. This paper presents a comprehensive review of existing modeling and stability analysis methods for VSC-dominated power systems, including their basic principles, key features, application scenarios and development tendencies. Key technical issues related to modeling and stability analysis are also summarized.