Dynamically Aggregated Small-Signal Impedance Model of Inverter-Based Resources

Abstract

Bulk renewable energy resources are interfaced with power systems by large-scale power plants having numerous inverter-based resources (IBRs). To alleviate the burden of simulating large networks, aggregated models are required to effectively emulate the large-signal behaviour in electromagnetic time-domain (EMT) simulations, and small-signal behaviour for analytical studies. This work develops a step-wise generic methodology for small-signal dynamic equivalencing of a renewable power plant considering realistic heterogeneity in IBRs' hardware, control parameters, control structures, and their distinct locations. Unlike many existing aggregation methods, the impact of passive elements and IBR set-points (active components) is also considered. The aggregated small-signal impedance model is verified using EMT simulations of various operating scenarios in MATLAB/Simulink. IEEE