Typhoon HIL Blog

While computer aided design tools have found wide adoption by practicing engineers, control testing has been lagging.

Most of the control system type testing is still done manually, in the lab, using small scale or large full scale power hardware, which can significantly prolong the time it takes to bring new power electronics products to market.

So why do practicing engineers use power hardware to test their control systems in the first place?

One good reason is that until recently there was no satisfactory alternative. Once the real time software is loaded to the DSP and the FPGA starts generating PWM pulses with nanosecond resolution, there is little else what can be done other than hooking it up to their inverters and slowly increasing the voltage, hoping that this time they won't hear a loud BANG.

Luckily, things are improving and powerful, commercially available controller hardware-in-the-loop (C-HIL) test equipment are becoming available. VDC Research Group, a technology market research company, predicted in their report "The Global Market for Hardware-in-the-Loop Testing Solutions" that the adoption of commercial C-HIL solutions for power electronics will depend on the speed at which new C-HIL solutions will be able to replace the in-house developed test rigs industries have been building over the decades.

What is Hardware-in-the-Loop?

Digital control and communication are playing an ever more important role in the field of power electronics and power system. C-HIL (Controller Hardware In the Loop) technology can strongly support this technological evolution  when applied in the learning process at undergraduate and graduate level.

Moreover it makes power engineering more hands on and interactive as well as accessible to undergraduate students because there are no dangers, costs and tight supervision requirements of the power laboratory.

Until recently there were practically no Hardware in the Loop (HIL) systems in the market developed specifically for power electronics and microgrid applications.  

This meant that only large companies in rail and aerospace could afford to add some power electronics HIL functionality on top of their general purpose HIL systems.

Nowadays, with powerful system on chip devices that combine the flexibility of general-purpose processors with the low latency of the FPGA fabric, a multitude of new vendors are competing for their place in this promising market.  

The multitude of competing offers and marketing messages creates confusion with the selection process.  This document will attempt to clarify by pointing out six important criteria that need to be considered when selecting your next HIL system.

Last year at the Applied Power Electronics Conference (APEC2016) I ran into a good friend of mine that I haven’t seen since the graduate school. He is now an accomplished R&D engineer in one of the leading power electronics companies.

After the initial conversation, trying to catch up on each other’s personal and professional accomplishments, we started to discuss the power electronics industry. I was eager to share my wisdom about Hardware-in-the-Loop (HIL) simulation and how it is radically changing the face of the (earth) power electronics and power systems. Frost and Sullivan Market Report.

I was shocked to see his face cringe in an utter disgust before I could even finish my spiel. He promptly fired back at me: “I’ve tried to use a HIL system and apart from the fact that it took me months to learn all the software tools needed to get it to run, the simulated waveforms were not even close to what I was expecting. I was continuously running into numerical stability issues and it took hours to prepare/compile models for simulation. Honestly, I never even got to the task of automating controller testing because I ran out of time and patience.” Before I was able to calm him down, he swore that he will never again use HIL simulation in his life.

I took it personally, since I am a big believer in HIL testing and tend to elevate HIL systems right next to the oscilloscope and power supply when it comes to the essential power electronics controls engineer toolbox For me it was rather troubling my friend had such a strong negative emotion for a development and testing method based on one system experience.

Understandably, his feedback was fueled by his deep frustration with what amounts to bad product design. However, just because a particular product is poorly designed does not mean that the overall method or application is wrong. If my brand new car consistently breaks down the first couple years I have it, I’m going to buy another car, but it’s definitely the last time I buy from that manufacturer.

Motivated on one side by examples of bad HIL design, and on the other side inspired by one of the greatest industrial designers of all time Dieter Rahms and his 10 principles of good design, I had to define what I would like to call 4 Principles of Good Hardware-in-the-Loop Design.