Bridging the Gap Between Interconnection Studies and Reality: Why Inverter-Based Resource Commissioning Matters More Than Ever

Ryan D. Quint, PhD, PE

President and CEO, Elevate Energy Consulting

President and Chief Engineer, GridStrong

At Elevate Energy Consulting, we help renewables developers, utilities, system operators, and other industry partners navigate the evolving energy transition with practical, proven strategies rooted in core societal needs of safe, reliable, and affordable electricity for all.

As North America accelerates its transition to higher penetrations of inverter-based resources (IBRs) like wind, solar, and battery energy storage alongside advanced transmission technologies like HVDC and E-STATCOMs, one truth stands clear: these assets don’t behave like traditional synchronous machines that formed the bedrock of reliable power for more than a century.

That difference — more software, more parameters, more control complexity — means the time-honored practices of generator commissioning, once relatively straightforward, now require a much sharper focus, greater discipline, and robust coordination between stakeholders.

So what can today’s generator owners, original equipment manufacturers (OEMs), and transmission operators learn from past grid events, North American Electric Reliability Corporation (NERC) alerts, reports, and guidelines, IEEE 2800-2022 and P2800.2 activities, and other industry efforts? Here are some of Elevate’s key messages, lessons learned, and takeaways for every utility and renewables developer – specifically related to IBR plant commissioning, which remains a vital aspect of grid reliability today more than ever.

Good Commissioning is Good Grid Citizenship

Synchronous generators, with spinning masses and relatively simple controllers, had a core focus on ensuring safety and reliability of the systems brought online for the integrity of the asset. As John Undrill always preached to me inside a power plant, “electricity is just a byproduct” of all the complex energy systems (primarily hardware, processes, and spinning mass) within a synchronous generator plant. By contrast, IBR behavior depends almost entirely on software: how its inverter firmware, protection logic, and power plant controller (PPC) are configured and tuned drive nearly everything.

A typical synchronous generator might have a handful of key parameters that are carefully and cautiously set and tested during commissioning. An IBR and its PPC? Many hundreds or even thousands of parameters, that come out of the box with default settings. Each parameter must be configured to deliver on what was promised – and these promises are made during the interconnection studies using models to represent that facility. Grid planners and decisionmakers rely on these models and study results to keep the system stable and make grid investment and operating decisions.

When these parameters don’t match between the models and the field configurations, real-world events look very different from the results of the models and studies. The 2021 and 2022 Odessa Disturbances in Texas, among a dozen other large-scale IBR events, for example, demonstrated that many of the facilities involved in the event failed to operate as expected. Where do these expectations come from? Models and studies. A sobering reminder that mismatches or omissions in the models and reality can lead to unexpected tripping, loss of revenue, and potentially grid instability during real-time operating conditions.

That’s where robust commissioning comes in: it’s the bridge that connects design and study to field reality.

From the Field to the Model and Back Again

The new best practice is simple in principle but demanding in execution: treat parameter verification as a closed loop. That means every key parameter tested and validated in the field must be traceable back to the models that grid engineers used—any tweaks in the field must loop back into the models that planners, transmission operators, and balancing authorities use to keep the lights on.

Before an inverter-based resource (IBR) plant goes live, as-built installation evaluations ensure what’s installed in the field truly aligns with what was designed and studied. This includes verifying:

• IBR units

• Collector systems and transmission lead lines

• Supplemental devices

• Equipment nameplate specifications

• Plant-level controller(s)

• Protection and control systems

This step checks that the models used during IBR plant design evaluation and system impact studies still match the actual firmware versions, settings, and control logic installed on-site. If there have been significant changes — such as firmware updates, control tuning, or protection adjustments — that could affect how the plant performs, a re-evaluation may be needed before energization.

For projects with long construction times, these reviews help ensure models, settings, and field performance stay aligned. Changes made during on-site commissioning that impact plant performance need to be reflected in updated IBR plant models, maintaining traceability and accuracy for ongoing system planning and operations.

In essence, this step bridges design and reality, ensuring every IBR plant starts its operational life grounded in validated, accurate, and standards-aligned performance — a cornerstone of maintaining reliability on a modern grid.

OEMs need to provide parameter verification reports that clearly translate model inputs into device settings. Generator Owners (GOs) should include contractual requirements for parameter transparency from OEMs. Ideally, industry would have standardized “IBR files” that can seamlessly and automatically translate as-left settings to IBR model parameters. This would be similar to standard parameterization the industry has long used for synchronous machines, exciters, etc. For Transmission Planners, some proof that what was studied is what was built should become an obligation. The industry has learned this the hard way:

1. Accuracy at the commissioning stage protects the entire interconnection process.

2. What happens at commissioning can affect how the plant operates for years to come.

Careful Commissioning is Not a Checkbox, It’s a Reliability Obligation

While commissioning is frequently a crunch time near the end of a new interconnection project when developers are trying to get their resource(s) online quickly and effectively, commissioning cannot be treated as just another milestone or deadline before commercial operation. It’s part of an ongoing commitment to supporting grid reliability.

Commissioning tests verify that an IBR plant conforms to the interconnection requirements and obligations established (e.g., IEEE 2800-2022 or local/regional Facility Interconnection Requirements) before it connects to the grid. These tests should confirm:

·         The facility performs as studied

·         Plant settings and firmware match design evaluations

·         The IBR can operate safely under normal and contingency conditions

·         Measurement and monitoring equipment meet required accuracy

Importantly, data from these tests should feed into post-commissioning model validation, ensuring planners and operators have models that match real-world performance, reinforcing system studies and operational decisions that will affect grid reliability for years to come.

Commissioning tests should generally only proceed when the IBR plant has been fully constructed, all units are ready for energization, and design evaluations and as-built installation evaluations are completed. Tests should be conducted under practical resource conditions (e.g., 90%+ of units online), recognizing that in real-world scenarios, full-load conditions may not always be available during commissioning.

Constraints (e.g., POI voltage limits, ambient conditions) encountered during testing need to be adequately documented and shared with transmission entities to maintain transparency and guide future system assessments.

Tests should include, but are not limited to, the following:

• Mode and Parameter Change Transitions: Smooth transitions between control modes should be tested on operational readiness and adherence to requirements. This may also include responsiveness to transmission setpoints and dispatch commands.

• Reactive Power Capability: Reactive power injection and absorption tests are conducted within system limits, verifying the plant’s capability to support voltage and reactive power needs. These tests, while limited by system conditions, provide valuable operational assurance and validation data. This is also the purpose of the NERC MOD-025 standard.

• Voltage and Reactive Power Control Modes: Voltage reference step tests (e.g., 1-3% voltage setpoint change) or shunt reactive device switching tests are performed to evaluate the plant’s dynamic voltage and reactive power response. These tests provide valuable insights for model validation and NERC MOD-026 compliance.

• Frequency Response: Small frequency steps are introduced to test the plant’s behavior under normal and curtailed conditions, confirming responsiveness while avoiding operation near plant limits. For BESS and PV systems, tests can capture both charge and discharge sequences. These tests are also used for model validation and NERC MOD-027 compliance.

• Return to Service Testing: Verifies that IBR plants do not restart unintentionally during out-of-bound conditions, ensuring safe and compliant return to service behavior.

• Harmonics and Power Quality: Power quality monitoring systems should assess harmonic current and voltage distortion during various operating conditions, capacitor bank switching, and across generation ranges. Results are compared with limits (e.g., IEEE 2800-2022 and/or IEEE 519 limits) and possibly used in harmonic studies.

• Protection System Verification: Protective functions (frequency, voltage, ROCOF, islanding, overcurrent) are verified to ensure they align with settings used in design evaluations and will not interfere unexpectedly with ride-through capabilities during system events.

• Measurement Infrastructure Validation: Measurement equipment locations, configurations, and data retention settings are verified to ensure event analysis, disturbance monitoring, and post-commissioning model validation efforts can be effectively executed.

Data collected during commissioning tests is critical. The data feeds into post-commissioning model validation, helps ensure models reflect real-world plant behavior, informs disturbance event analysis and system reliability assessments, and supports continuous improvements in plant settings and operational performance.

Lessons Learned, Shared, and Applied

As NERC continues to emphasize in its recent Inverter-Based Resource Performance Subcommittee (IRPS) efforts, “organizational memory” is a critical aspect of effective and efficient IBR plant commissioning. Stakeholders should maintain living databases of information, data, and lessons learned.

• Which data is the latest for the site upon commissioning?

• How are data, settings, configurations, protections, and other site information stored in a way that is easily retrievable and useable by plant personnel and technical staff?

• What commissioning practices work most effectively and result in the most positive outcomes?

• What types of mistakes or failures may occur and how is the organization learning from these?

Sharing lessons across projects, across companies, and across interconnections strengthens the whole system. In an industry that has always prized institutional knowledge and steady practice, this is one tradition we should carry forward into the inverter-based era.

Getting the Basics Right: What Robust Commissioning Looks Like

A properly run commissioning process for an IBR facility should cover:

• Site-Specific Commissioning Plans: Clear roles, responsibilities, and checklists developed early and refined as the project progresses; these should be mutually agreed upon by the interconnection customer and the transmission provider.

• As-Built Physical and Electrical Evaluations: Confirming that the installation matches the design — every component, configuration, device, mode, protection, control, setting, and parameter.

• Functional Parameter Verification: Extracting real parameter settings directly from field devices, verifying them against design models, and providing traceable documentation.

• Comprehensive Commissioning Tests: Validating the plant’s active and reactive power responses, frequency ride-through, ramp rates, curtailment functionality, coordination with the grid operator’s control center, and other performance characteristics perform as expected and reliably.

• Post-Commissioning Model Validation: Confirming that the final study models match actual performance, providing updated models back to the transmission planner for review, as needed.

• Periodic Re-Tests: Keeping models current as real-world conditions change.

Moving Forward — Honor the Old, Embrace the New

The grid’s future must build upon the discipline that made the North American system the envy of the world: rigorous engineering, clear communication, shared responsibility for reliability, and continuous innovation.

Strong commissioning is not just a check-the-box exercise — it is an investment in the shared trust between generator owners, OEMs, transmission operators, and ultimately, every customer who expects their lights to stay on.

As we at Elevate support our industry partners through the energy transition, we hold fast to what the industry has always known: models matter, good engineering pays off, attention to detail succeeds, good commissioning is not optional, and grid reliability rules.

If you’re a renewables developer, utility, or regulator seeking support or practical guidance regarding how to link models, commissioning, and regulatory compliance together, we're here to help. Let’s build a resilient, reliable grid of the future together.

Visit us at www.elevate.energy to learn more or get in touch with our team of experts.