Introduction

From a power system generation perspective, GridLAB-D™ objects categorize generators by:

• physics-based models, and
• grid integration and interaction control for additional grid services.

Physics-Based Models for Grid Stability and Dynamics. Physics-Based Models group generators by how they interact with the grid's physical variables like frequency, voltage, and rotor angles. GridLAB-D™ provides objects for

• Synchronous Generators: traditional thermal, hydro, diesel, and nuclear plants. They couple directly to grid frequency, providing natural rotary inertia and high short-circuit current to stabilize voltage.
• Inverter-Based Resources (IBRs): solar PV, wind turbines, and battery storage. They use power electronics to convert DC or variable AC to grid frequency.
• Grid-Following (GFL) IBRs: most current modes for wind and solar generators. They require an existing grid voltage signal to lock onto and inject current.
• Grid-Forming (GFM) IBRs: advanced modern inverters. They act as a voltage source, capable of black-starting a grid and mimicking physical inertia.

Managerial and Controlling Models for Dispatch and Economics. Managerial models allow generators to participate in certain grid services, such as

• Secondary frequency control to maintain grid stability through Automatic Generation Control (AGC), and/or
• Generator synchronization to coordinate the connection of distributed generation units to the grid.