Islanded Operation of an Inverter-based Microgrid Using Droop Control Technique

Overview

Three parallel inverters operating in islanded mode with P/F and Q/V droop control plus supervisory frequency and voltage restoration.

This example demonstrates islanded operation of an inverter-based microgrid using droop control. It is a strong reference model for studying autonomous operation, power sharing, and voltage-frequency restoration without relying on PLL-based synchronization.

The microgrid contains three parallel inverters rated at 500 kW, 300 kW, and 200 kW. Each inverter includes a two-level converter, LC filter, 480/600 V transformer, DC source, and a complete control system. A dynamic load lets you apply realistic disturbances.

This model is excellent for both research and teaching. It illustrates core microgrid control concepts and gives users something immediately meaningful to discuss: droop tuning, load sharing quality, harmonic reduction, and secondary control performance.

Key Features

  • P/F and Q/V droop characteristics
  • Power sharing proportional to inverter size
  • Supervisory control to restore 60 Hz and 600 V nominal values
  • Harmonic analysis possibilities using carrier phase variation

Getting Started

  1. Run the model and monitor inverter power sharing.
  2. Observe the load increase at 1 s.
  3. Watch droop control enable at 3 s.
  4. See supervisory restoration take effect at 5 s.

Model Specifications

Parameter Value
Product SPS Software
Simulation type Real-time
Software version SPS Software 2025+ (with RT-LAB)
Recommended time step Not published — switching content ~2700 Hz; confirm in model
Real-time solver ARTEMiS (CPU real-time)
Compatible hardware OP4605XG2, OP4610XG2, OP5020XG2, OP5025XG2, OP5033XG2, OP5707XG2
Model file Coming soon

Downloads

The downloadable model package is coming soon.

Microgrid_IslandedOperation_DroopControl.zip (140.7 KB)

When you tune droop control in islanded systems, do you prioritize proportional load sharing, tighter voltage regulation, or harmonic performance first?