Grid Forming (GFM) Modeling

Advanced inverter-based resource modeling for next-generation grid stability and renewable integration

What is Grid Forming (GFM) Modeling?

Grid Forming (GFM) modeling involves the analysis and design of inverter-based resources that can establish and maintain grid voltage and frequency, similar to conventional synchronous generators. Unlike grid-following inverters, GFM inverters can operate independently and provide essential grid services.

As power systems transition to higher renewable penetration, GFM technology becomes crucial for maintaining grid stability and enabling the operation of weak grids and microgrids.

GFM vs Grid Following (GFL)

Grid Forming (GFM)

  • Controls voltage magnitude and frequency
  • Can operate in islanded mode
  • Provides inertial response
  • Supports weak grid conditions

Grid Following (GFL)

  • Controls active and reactive power
  • Requires strong grid connection
  • Follows grid voltage and frequency
  • Limited grid support capabilities

GFM Control Strategies

Droop Control

Mimics synchronous generator behavior with frequency and voltage droop characteristics.

Virtual Synchronous Machine (VSM)

Emulates the inertial and damping properties of rotating machines.

Dispatchable Virtual Oscillator Control (dVOC)

Provides fast synchronization and improved stability.

Virtual Impedance Control

Shapes output impedance for improved power sharing and stability.

Benefits of GFM Modeling Studies

Grid Stability

Enhanced system stability with high renewable penetration.

Black Start Capability

Ability to energize dead grids without external power sources.

Microgrid Operation

Seamless islanding and reconnection capabilities.

Grid Services

Provision of frequency regulation, voltage support, and inertial response.

Weak Grid Support

Operation in low short-circuit ratio conditions.

Power Quality

Improved voltage and frequency regulation.

How We Perform GFM Modeling Studies

1

System Assessment

Evaluate grid conditions and GFM requirements.

2

Control Design

Develop appropriate GFM control strategies and parameters.

3

Dynamic Modeling

Create detailed GFM inverter models in PSCAD/EMTDC or MATLAB/Simulink.

4

Stability Analysis

Assess small-signal and large-disturbance stability.

5

Performance Testing

Evaluate response to grid disturbances and load changes.

6

Grid Code Compliance

Verify adherence to emerging GFM grid codes and standards.

GFM Applications

  • Utility-scale solar and wind farms
  • Battery energy storage systems
  • Microgrids and distributed energy resources
  • HVDC converter stations
  • Industrial power systems
  • Remote area power supply systems

Study Deliverables

  • GFM control system design specifications
  • Dynamic performance analysis reports
  • Grid interaction study results
  • Stability assessment and recommendations
  • Grid code compliance verification
  • Control parameter optimization

Key Performance Metrics

Frequency Response

Inertial response, primary frequency control

Voltage Control

Voltage regulation, reactive power support

Stability Margins

Small-signal, transient stability

Power Quality

THD, voltage unbalance, flicker

Standards and Guidelines

IEEE 2800

Standard for Interconnection and Interoperability of Inverter-Based Resources.

IEC 61400-21-1

Wind energy generation systems - Electrical characteristics (Grid forming capability).

NERC Reliability Guidelines

Inverter-Based Resource Performance Guidelines.

CIGRE TB 832

Technical requirements for grid forming converters.