How Hardware in the Loop Tests the Functionality of Microgrid Controllers

In the fourth article of this special report series brought to you by Microgrid Knowledge and Typhoon HIL, we’re looking at how Hardware in the Loop (HIL), specifically controller Hardware in the Loop (C-HIL), is an ideal technique for testing the functionality of microgrid controllers.

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The IEEE’s 2030.8-2018 Standard for the Testing of Microgrid Controllers recommends C-HIL as an appropriate method for testing microgrid controller functionality, such as islanding and dispatching. The controller is difficult to model realistically, but it’s often easier and cheaper to modify than the rest of the hardware. As such, organizations like Typhoon HIL apply high-fidelity C-HIL methodologies by putting physical controllers into HIL devices and connecting them through HIL-connected interfaces.

Up until now, real-time simulation has focused on transmission, but it is becoming more commonly used in distribution systems and for microgrids. HIL testing de-risks the process of designing, integrating and configuring the piece of hardware under test, such as microgrid controllers or protective relays.

According to Ryan Smith, chief technology officer at EPC Power, the power electronics converter company relies on C-HIL testing. EPC Power uses C-HIL testing to develop and test its battery storage inverter controller software. Its software development team continuously tests software to verify performance and specification with C-HIL.

EPC Power also provides system integrators with its HIL Compatible inverter model, which can run in real-time. System integrators can use this model to perform virtual system integration, verify system performance, adjust protection settings and test different faults conditions.

Scott Manson, technology director at Schweitzer Engineering Laboratories, raises a learning and development opportunity for engineers. Indeed, a C-HIL test bed is a high-fidelity “flight-simulator” for microgrids. An engineer working with a HIL system can deal with a “lifetime of career experience consolidated into a week,” experiencing thousands of diverse faults during testing.

For more details, download the full report. Source: NDC

When it comes to the cost of developing HIL models, the size and complexity of the microgrid play a role. In general, if the microgrid is in the megawatt scale and contains a diverse range of DERs, HIL can be a cost-effective investment. Some business models are shifting toward HIL as a service, simplifying the process. For a military application using its microgrid as a backup for mission critical applications, a high value is placed on the assurance that the system will work under any fault condition or in any scenario, which can be provided by exhaustive HIL testing.

Those already using HIL testing do experience benefits. According to research carried out by VDC, respondents who used HIL reported a mean reduction of 28% in total project cost and a reduction of 47% in the number of associated man-hours.

In addition, VDC’s survey showed that projects using HIL testing were more likely to be on or ahead of schedule than those not using HIL. They were also able to produce systems with an average of 42% more lines of code, and they experienced a 38% reduction in software defects in the deployed product.

Taking this into account, it is clear that applying HIL methodologies to microgrid projects not only improves system integration, but the overall delivery of the project. Even further improvements were reported to VDC by projects that used a combination of HIL and model-based engineering.

Next week, this special report series will take a look at how Hardware in the Loop (HIL) and model-based engineering can streamline microgrid development.

And check out the previous articles in the series below:

Download the full report “How Hardware in the Loop Addresses Challenges of Microgrid System Integration” courtesy of Typhoon HIL to learn more.