Tutorial: Grid-Following Inverter for Electrical Power Grid

TL;DR

This tutorial provides a circuit-theoretic introduction to modeling, control, and simulation of grid-following inverters in power systems, connecting control design with time-domain simulation from first principles.

Contribution

It offers a comprehensive, first-principles-based tutorial on modeling and simulating grid-following inverters, bridging control design and electromagnetic transient simulation.

Findings

Detailed inverter synchronization with the grid (PLL) explained

Control structures for power and current regulation described

Simulation framework connects circuit models with EMT platforms

Abstract

The growing use of inverter-based resources in modern power systems has made grid-following inverters a central topic in power-system modeling, control, and simulation. Despite their widespread deployment, introductory material that explains grid-following inverter operation from first principles and connects control design to time-domain simulation remains limited. To address this need, this tutorial presents a circuit-theoretic introduction to the modeling and simulation of a grid- following inverter connected to an electrical power grid. We describe the inverter synchronization with the grid (PLL), power control, and current control structure and show how these elements can be represented within an electromagnetic transient (EMT) simulation framework using companion model-based formulations similar to those used in circuit simulators such as SPICE and Cadence. In this tutorial, we use the grid-following inverter as the primary example to illustrate how its governing equations, control loops, and network interface can be formulated and simulated from first principles. By the end of the document, readers should gain a clear introductory understanding of how to model and simulate a grid-following inverter in an EMT platform.