New-Tech Europe Magazine | May 2018

engineers developing converters, HIL is also extremely useful to microgrid engineers, shipboard-power system engineers, system integrators, and is also guaranteed to be a life-changing tool for QA engineers. Additionally, HIL is the best productivity hack for every engineer who finds it increasingly difficult to make sure that new control software/firmware updates of power devices meet standard-based certification requirements such as those issued by BDEW or UL. Additionally, HIL is also becoming indispensable for all electric vehicle (EV) applications, whether the EV is terrestrial (e.g. automotive – a car, or transportation – e.g. a next-generation train), marine (UMSs), or airborne (UAVs). At this point, some may object to this claim by saying that the engineers working on vehicles were the first ones to embrace the concept of HIL as early as in the 90s. That is correct. However, the HIL systems employed in such applications are focused on controllers of mechanical systems, where the emulation timestep of 1 millisecond (ms) is sufficient. Fast- switching PE systems used in EVs, such as kinetic energy recovery systems, fast chargers, battery management systems, etc., require HIL systems that operate on a completely different timescale: the HIL systems from the domain of PE, capable of timesteps as low as 1 µs, or even 500 ns. In short, EV engineers who expand their current HIL systems with the addition of power-electronics HIL (i.e. C-HIL) can expand the scope of their HIL testing beyond mechanical systems and include the fast-switching PE devices into their test coverage, thus creating true digital twins of their vehicles. Finally, from the organization point of view, HIL is a perfect tool for onboarding and the common ground for functional integration of geographically- distributed, multi-department projects in large companies and/or enterprises.

Figure 1: Components of a typical HIL testing setup, as used for development of smart inverters

Thanks to its zero-risk environment based on virtualized power, HIL facilitates rapid staff turnovers, agile product development and efficient onboarding, because new engineers can quickly get familiar with pre-existing products and solutions and learn how they work in an interactive way, where the effects of changing every line of control code can be immediately seen by means of real-time HIL testbeds and HIL SCADA. HIL also provides a solution for geographically distributed teams working on complex projects, because every team can use the same platform (low initial cost at low risk) to immediately see the effects of their contributions to the overall system, before committing the changes. All this may sound too good to be true, but, as engineers who have embraced the HIL methodology will tell you, it gets even better, because HIL ultimately makes engineering work less stressful and provides a way for safe and quick experimentation with new ideas and alternative approaches. High quality power products need extensive testing. Testing the power products has high energy costs, high infrastructure costs and high failure risks. Read on for

detailed benefits of HIL based on actual use cases by HIL users. What are the benefits of using HIL? The introduction of the HIL paradigm brings about one or more of the following five benefits: enhanced test coverage, streamlined product certification, lower R&D costs, simplified system integration, improved product, and, ultimately, lower OPEX. Enhance your software control test coverage The biggest, overarching benefit of using HIL and the emulated power stage is that it enables engineers to focus only on control and make the controller completely bug-free and fully optimized, before even starting tests with real power in a fancy and spacious power lab. This, by the way, is the most logical approach to power electronics development: test with real power only once you are confident that the software which controls it is error-free (or at least fatal error-free). In other words, by adopting HIL in all the stages of the development pipeline leading up to physical testing, engineers can be absolutely confident that physical testing with real power

New-Tech Magazine Europe l 53