HIL+ Testing: Bringing Physical Electromechanical Systems Into Hardware-in-the-Loop Testing for AI Data Centers

Hardware-in-the-Loop (HIL) testing has become an important part of validating modern power systems, allowing engineers to test real controllers and electrical hardware against a simulated power system before field deployment. However, for applications such as AI data centers with onsite generation, electrical and control hardware are only part of the system.

At EdgeTunePower (ETP), we have initiated a new testing concept called HIL+, which takes conventional HIL testing one step further by bringing the physical mechanical system into the loop.

What Is HIL+ Testing?

AI data center loads can change very quickly. When a facility relies on onsite generation, those fast load variations can translate into disturbances seen directly by generators and their mechanical systems.

This raises practical questions:

What happens to a generator shaft when an AI load changes rapidly? Can these changes excite electromechanical or torsional oscillations? And can a BESS respond quickly enough to reduce those effects?

These are exactly the types of questions HIL+ is intended to investigate.

ETP has successfully demonstrated the HIL+ concept for an AI data center interconnection with onsite generation. Our testing investigated:

• The impact of fast AI load variations on generator shafts

• Electromechanical and torsional oscillations

• The effectiveness of BESS in damping these oscillations

• The performance of ETP's IT-SSO-5/55 mitigation solution

  
  

The important part is that these interactions were demonstrated with physical equipment at laboratory scale before taking the solution to a GW-scale facility.

Why Does HIL+ Matter for AI Data Centers?

AI data center loads can change rapidly, creating disturbances for onsite generation and mechanical systems. This raises important questions: How do fast AI load variations affect generator shafts? Can they cause electromechanical or torsional oscillations? Can BESS help damp these effects?

ETP demonstrated HIL+ for AI data center interconnection with onsite generation, investigating generator shaft response, electromechanical and torsional oscillations, BESS-based damping, and the performance of ETP’s IT-SSO-5/55 mitigation solution—all with physical equipment at laboratory scale before deployment at a GW-scale facility.

How Is HIL+ Different From Traditional HIL?

HIL+ does not replace simulation or conventional HIL testing. It adds another layer of validation when electrical and mechanical dynamics are closely coupled.

From the Lab to GW-Scale Data Centers

A GW-scale data center cannot be recreated in a laboratory, but its critical dynamics can be represented through real-time simulation with physical equipment in the test loop. This allows interactions between onsite generation, BESS, power electronics, and dynamic AI loads to be identified and validated before commissioning or full-scale operation.

Frequently Asked Questions

What does HIL+ mean?

HIL+ is a testing concept initiated by ETP that extends traditional Hardware-in-the-Loop testing by incorporating physical electromechanical equipment into a real-time power-system simulation.

Why use HIL+ for AI data centers?

Fast AI load variations can interact with onsite generators and create complex electrical and mechanical dynamics. HIL+ allows these interactions to be investigated using physical equipment in a controlled laboratory environment.

Can HIL+ evaluate generator shaft and torsional oscillations?

Yes. ETP has used HIL+ to investigate generator shaft response and electromechanical and torsional oscillations resulting from dynamic AI data center loads.

Can HIL+ be used to evaluate BESS-based mitigation?

Yes. HIL+ can be used to investigate how BESS controls respond to rapid load changes and whether they can help damp oscillations experienced by onsite generation.

De-Risking AI Data Center Power Systems Before Deployment

As AI data centers become larger and increasingly dependent on onsite generation, understanding the interaction between the electrical and mechanical sides of the power system becomes more important.

HIL+ gives engineers another way to investigate those interactions before reaching the field.

Contact EdgeTunePower to discuss HIL+ and how it can support the validation and de-risking of your GW-scale AI data center project.