Preserving Existence of Equilibrium Point for Renewable Energy Source Dominated Power System

A methodology to determine and preserve Existence of Equilibrium Point (EoEP) is proposed for a power grid dominated by Renewable Energy Sources (RESs). Starting from phasor-domain circuit analysis, a sufficient criterion of assessment in determining EoEP is derived with the theorem of implicit function and analytic continuation. As an outcome of assessment, an indicator, namely the Generalized Short Circuit Ratio (
gSCR
) is applied to indicate the risk of loss-of-equilibrium for a multi-bus system. Based on
gSCR
, a decentralized control strategy to prevent loss-of-equilibrium against excessive under-voltage is proposed accordingly. The effectiveness of proposed methodology is verified in case studies with pseudo-steady state simulation, static Monte Carlo method and dynamic EMT simulations.