Hardware-in-the-loop testing
Hardware-in-the-loop (HIL) simulation is the gold standard for developing and validating the most advanced control, protection, and monitoring systems. As products grow more complex and time-to-market pressures mount, HIL enables fast, safe, and scalable testing without the need for physical prototypes. Our hardware-in-the-loop testing solutions are trusted across industries for their reliability and real-time accuracy.
A smarter approach to system testing
Why HIL testing is replacing traditional methods
Testing of control systems has traditionally been carried out directly on physical equipment (i.e. plant) in the field, on the full system, or on a power testbed in a lab. While offering high-fidelity results, this practice can be costly, inefficient, and potentially unsafe. Hardware-in-the-loop testing offers a powerful and scalable alternative. The physical plant is replaced by a real-time simulation model running on a simulator equipped with I/O capable of interfacing with control systems and other equipment.
This enables accurate, closed-loop testing of plant behavior—including sensors and actuators—without relying on real systems. By reducing risk, cost, and development time, HIL simulation testing has become the global standard for validating complex embedded systems.
Solution
How hardware-in-the-loop works
HIL simulation involves replacing a real system with a real-time simulation model that interacts dynamically with a device under test (DUT). This approach is a core part of hardware in the loop testing, enabling accurate and repeatable results. This allows engineers to test how the DUT will behave in a variety of real-world and edge-case scenarios, without physical risks. With a HIL tester, we can exchange signals, both analog and digital, between the DUT and the simulator to validate system behavior quickly and safely. From communication interfaces to electrical signals, the simulator exchanges data with the DUT in real time, enabling fully integrated and iterative testing of embedded control systems.
Benefits
Accelerated development and safer testing
HIL simulation empowers developers and test engineers to innovate faster, reduce cost, and test systems safely.
01
Save time
Today’s compressed timelines and supply chain delays make waiting for prototypes a luxury. With HIL simulation, up to 95% of testing can be completed before hardware even exists.
02
Cut costs
HIL testing is more economical than using expensive physical plants or full-scale testbeds. Simulators are reusable and adaptable, leading to significant cost savings.
03
Reduce risk
HIL simulation lets you push systems to their limits—without pushing real equipment over the edge. Test edge cases, fault scenarios, and failure modes to identify vulnerabilities early.
04
Ensure safety
HIL ensures control systems behave as expected—before touching real equipment. Protect your people, infrastructure, and equipment, and ensure safe, repeatable testing under even the most hazardous conditions.
Applications
Used across industries
HIL simulation is a critical tool in any domain where control, protection, or monitoring systems are developed. It’s trusted by engineers, researchers, and educators to de-risk testing and accelerate innovation.
Energy
Validate protection, stability, and integration of renewables
Power electronics
Test converters, inverters, and power systems dynamically
Automotive
Develop EVs, battery management, and driver-assist systems
Aerospace
Simulate flight control, avionics, and propulsion systems
Academia and research
Enable cutting-edge education and innovation
Autonomy
Accelerate the development of autonomous vehicles and robots with real-time sensor simulation and co-simulation tools
What our clients say
Real-world success stories with HIL
We decided to use OPAL-RT amongst other choices of HIL systems because of their widespread research and industry use, fast and accurate emulation of the complex power electronics hardware, and great customer support.
magniX
In a recent product pre-research project, we successfully completed over a hundred software functionality tests using RT-LAB’s automation features, saving approximately 50% of the testing time compared to traditional physical test benches.
Sungrow
Our old simulator did not have real-time simulation capabilities, and so we simply did not have the flexibility that we do now to introduce many and various ‘what if’ case scenarios. We can now model our distribution portion as well as our transmission—it has been great for us in the system protection technical training program, both for all the instructors and the students.
Dominion Energy
Developing power hardware, a costly and time-consuming process, [is] one worth streamlining and shortening. We saw a strengthening of the development cycle through introducing all possible system variations, such as grid impedances, harmonics, voltage variations in the control law design, and tests before the final product— doing a thorough troubleshooting ahead of all this.
Valeo
With HIL, one of the biggest advantages is being able to test the actual product. We can simulate all sorts of use cases: 50 Hz grids, multiple stacked units, different grid impedances, balanced and unbalanced loads– all kinds of situations.
Schneider Electric
FAQ
Find the answers to your questions
What communication protocols do you support?
Consult our comprehensive list of supported protocols here: Communication Protocols.
What is hardware-in-the-loop (HIL) testing, and how does it work?
Hardware-in-the-loop (HIL) testing is a technique where we replace a physical system—such as an electric motor, power grid, or mechanical plant—with a real-time simulation model. This simulation runs on our high-performance HIL tester and interfaces with the actual control hardware through I/O. By doing so, we can validate system behavior under real-world conditions—without needing the physical equipment.
Why should we choose HIL testing over traditional methods?
Traditional testing often requires expensive prototypes, full-scale systems, or power labs, which can be risky and time-consuming. Our hardware-in-the-loop HIL testing eliminates those challenges. We simulate the plant in real time, enabling us to test and iterate quickly, safely, and cost-effectively—making HIL simulation testing the smarter approach for modern embedded system validation.
What types of systems can we validate using HIL simulation testing?
Our HIL simulation testing is ideal for validating advanced control, protection, and monitoring systems across industries. Whether we’re working on an EV battery management system, a power grid controller, or an aerospace ECU, our hardware-in-the-loop solutions provide the accuracy and flexibility to simulate a wide range of real-world conditions and edge cases.
How does using a HIL tester accelerate development cycles?
By using a HIL tester, we can rapidly prototype and test control systems in a closed-loop environment—without needing physical hardware. This speeds up development by enabling us to detect and resolve issues early, iterate on design changes faster, and run automated test scenarios continuously, all of which help us meet tight time-to-market demands.
What makes OPAL-RT’s hardware-in-the-loop testing solutions stand out?
Our HIL solutions are designed for openness, scalability, and performance. With real-time digital simulators, powerful I/O systems, and industry-specific toolboxes, we offer a HIL test environment that integrates seamlessly with your existing workflow. We help engineers go from imagination to real-time with unmatched speed, safety, and accuracy.
Ready to accelerate your development?
Get in touch with our experts today! Whether you’re looking to speed up testing, reduce costs, or ensure the safety of your systems, we have the right HIL solutions for you. Let’s talk about how we can help optimize your product development process.