Circuit-based two-stage bidirectional Iinverter model for grid analysis and optimization

The growing penetration of distributed energy resources (DERs)—such as photovoltaic and battery systems—requires accurate inverter models for reliable power flow analysis and grid optimization. Existing approaches often simplify inverter behavior using constant-efficiency as- sumptions, neglecting key loss mechanisms and reactive power effects. This work introduces a circuit-based two-stage bidirectional inverter (TSBI) model that captures switching and conduc- tion losses and LCL filter dynamics in a steady state. Validated on large-scale feeders, the TSBI enables accurate voltage and efficiency estimation and supports control strategies like maximum power point tracking and Volt–VAR, addressing limitations in conventional grid studies.