A Practical Guide with DIgSILENT PowerFactory

As renewable energy, battery storage, and large industrial loads accelerate across Saudi Arabia and the United States, grid connection is no longer a formality, it is a technical and regulatory bottleneck. Utilities and system operators now require comprehensive Grid Impact Studies (GIS) before approving any new connection to transmission or distribution networks.

To meet these expectations efficiently and credibly, engineering teams are increasingly standardizing on DIgSILENT PowerFactory a proven platform for utility-grade power system studies across renewables, BESS, and industrial facilities.

This guide explains what Grid Impact Studies involve, how requirements differ between Saudi Arabia and the USA, and how PowerFactory enables faster, approval-ready study delivery.

What Is a Grid Impact Study?

A Grid Impact Study evaluates how a proposed connection such as solar PV, wind, BESS, hybrid plants, or large industrial loads—affects the existing power system.

Utilities require these studies to ensure:

• Voltage and thermal limits are not violated

• Fault levels remain within equipment ratings

• System stability is maintained during disturbances

• Protection systems continue to operate selectively

• Grid codes and interconnection standards are met

Failure to pass a Grid Impact Study results in connection delays, redesign costs, or outright rejection.

Why Grid Impact Studies Matter in Saudi Arabia and the USA

Saudi Arabia: Grid Code–Driven Compliance

Saudi Arabia’s power sector is expanding rapidly with large-scale renewables, giga projects, and industrial electrification. The Saudi Arabian Grid Code (updated May 2024) formally defines the connection process and includes Grid Impact Studies as a mandatory step.

For distribution-level projects, Saudi Electricity Company (SEC) enforces technical standards for renewable generator-based systems connected to LV and MV networks.

Key takeaway: In Saudi Arabia, grid studies must be structured, traceable, and explicitly aligned with Grid Code and SEC requirements.

United States: Interconnection Reform and Reliability Expectations

In the USA, grid impact requirements are shaped by:

• FERC Order 2023 / 2023-A, which reforms generator interconnection procedures to improve speed, transparency, and study discipline

• NERC Transmission Planning (TPL) standards that influence how utilities assess steady-state, short-circuit, and stability performance

• IEEE 1547-2018, which defines DER performance and ride-through behavior for distribution-connected resources

Key takeaway: US utilities expect repeatable, audit-ready studies that can withstand restudies and regulatory scrutiny.

Why DIgSILENT PowerFactory Is the Industry Standard

DIgSILENT PowerFactory is widely adopted by utilities, consultants, and EPCs because it supports the full lifecycle of grid studies in a single model environment.

PowerFactory enables:

• IEC and ANSI short-circuit calculations

• Load flow and contingency analysis

• RMS dynamic and transient stability studies

• EMT (electromagnetic transient) simulation for inverter-dominated grids

• Integrated protection modeling and coordination

• Consistent reporting and model governance

This makes PowerFactory ideal for projects that must meet both Middle East and North American utility expectations.

A Practical PowerFactory Workflow for Grid Impact Studies

1. Network Modeling and Data Governance

A successful Grid Impact Study starts with a defensible base model.

This includes:

• Accurate network topology and equipment ratings

• Generator and inverter models with correct control modes

• Transformer tap ranges and reactive compensation

• Clear version control (base case vs proposed case)

Outcome: A traceable model that utilities can trust.

2. Load Flow and Voltage Analysis

Steady-state analysis evaluates system performance under:

• Peak and off-peak conditions

• Normal (N-0) and contingency (N-1) scenarios

• Maximum generation and minimum load cases

PowerFactory outputs:

• Voltage profile compliance

• Thermal loading on lines and transformers

• Reactive power margins and control behavior

3. Short-Circuit and Fault Level Studies

Short-circuit analysis ensures:

• Circuit breakers are not overstressed

• Fault levels remain within equipment ratings

• New inverter-based resources do not create weak-grid risks

PowerFactory supports IEC 60909 and ANSI/IEEE fault calculation methods, making it suitable for both Saudi and US networks.

4. RMS Dynamic and Stability Studies

Dynamic studies assess how the grid responds to disturbances such as:

• Three-phase faults and fault clearing

• Generator or load tripping

• Line or transformer outages

• Frequency and voltage recovery

These studies are critical for large renewables, BESS, and industrial loads connected to weak or highly loaded networks.

5. EMT Studies for Inverter-Dominated Systems

As inverter penetration increases, many utilities now require EMT studies.

EMT simulations in PowerFactory are used to analyze:

• Switching and temporary overvoltages (TOV)

• Inrush currents and resonance

• Converter control interactions

• Fast transient behavior beyond RMS capability

This is often a decisive approval requirement for BESS and large solar PV plants.

6. Protection Coordination and Compliance Mapping

Grid Impact Studies must also confirm:

• Selective protection operation

• Coordination between feeders, transformers, and generators

• Alignment with utility protection philosophies

Final reports should explicitly map results to Grid Code, SEC, FERC, NERC, and IEEE 1547 expectations, not just present raw plots.

What Utilities Expect in a Final Grid Impact Study Report

Approval-ready reports typically include:

• Study assumptions and data sources

• Defined study cases and scenarios

• Clear pass/fail criteria

• Mitigation measures for any violations

• Appendices with model parameters and plots

Professional presentation directly impacts approval timelines.

Commercial Advantage of PowerFactory-Based Studies

For developers, EPCs, and industrial clients, PowerFactory studies deliver:

• Faster approvals

• Reduced restudy risk

• Lower project uncertainty

• Stronger lender and utility confidence

For service providers, it enables scalable, repeatable delivery across regions.

Conclusion

Whether connecting a solar PV plant in Saudi Arabia, a BESS project in Texas, or a large industrial facility anywhere in between, Grid Impact Studies are now a business-critical requirement.

DIgSILENT PowerFactory provides the technical depth, regulatory flexibility, and credibility required to deliver utility-grade Grid Impact Studies for both Saudi Arabian and US power systems efficiently and with confidence.