New-Tech Europe Magazine | May 2018

HIL improves test coverage, lowers R&D costs and streamlines certification processes, leading to better products and lower OPEX.

What is HIL in power electronics? Aleksandar Kavgic, Typhoon HIL Inc. and Adrian Zuckerberger, A2Z Consulting Ltd. methodology for testing should be only the final stage in the product development cycle. The ideal HIL approach, conversely, for most of the power electronics development cycle is what some call C-HIL (Controller- Hardware in the Loop), which is the meaning of the acronym as used in the reminder of the article. This means that a real controller – a PCB (not the entire device) is connected to a real-time model of the power stage. In short, the controller, together with its embedded software/firmware, is “fooled” into believing that it controls real power, but is actually interfaced to a high-fidelity real time emulation of the power stage and/or grid. HIL, short for Hardware In the Loop, is often associated with taking a device under test (DUT) to a lab, powering it on and assessing its performance in various scenarios, such as steady state, transients, and different supply system malfunctions, e.g. short circuits, power sags, etc. In this, traditional, view of HIL, the power used for testing the DUT is real. The hazards to which engineers are exposed are real, too. Finally, the damage to a DUT prototype, when it occurs, is real, as are the costs of repairing or producing a new DUT prototype. Therefore, this approach is often called P-HIL, short for Power-Hardware In the Loop. In power electronics (PE), however, HIL may refer to a different methodology. Namely, in PE, where the focus is on control, the traditional, P-HIL, with I/O to connect the controller(s), on the one hand, and modelling, control, and automation software, on the other (Fig. 1). Who should be using HIL in development and production? HIL is a perfect match for PE engineers developing fast-switching systems, such as different converter topologies, e.g. inverters for PV systems, but it would be unwise and short-sighted to see its benefits restricted only to these applications. If seen for what it is – a control-focused improvement for pre- existing testing and R&D workflows, and not a replacement for everything that was used before – its benefits and reductions in OPEX are sure to resonate beyond the converter/inverter domain, and to go throughout the enterprise and even beyond traditional PE areas. More specifically, in addition to PE Ultimately, HIL allows direct insight into the behavior of control software, devoid of any hazards, damage and costs associated with testing in a power lab. A HIL system, which makes this possible, comprises a real-time hardware emulator

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