Power is arguably the most important aspect of modern societal infrastructure. Once you create civilization, you need to develop a means to accomplish tasks humans cannot accomplish without external help. Draft animals lead to systems powered by steam, fossil fuels, and electricity. The most important aspect of an electrical system is that it is signal/power/conversion agnostic, with the same electrons doing different tasks in an interconnected solid-state solution.
Any other power system, no matter how futuristic or magical, requires system conversions beyond rectification and isolation. Hydrogen fuel cells require liquid storage, maintenance, and security measures completely different from those required by the other electronic subsystems, for example. The same goes for any hybrid system requiring air as part of the power generation architecture.
The growing recognition of the superiority of a completely electromechanical solution based on stored energy easily converted to current is being manifested in the latest advanced automotive, robotic, and aeronautical e-mobility solutions being created to address a growing number of applications empowered by advanced electronics. However, behind it all, the need for accurate, efficient, and reliable power management systems is paramount.
We met with Robert Gendron, CMO at Vicor, to talk about the changing role of power electronics in the modern world. Vicor recently won the 2020 Global Semiconductor Alliance (GSA) Award for Analyst Favorite Semiconductor Company. The company is known for its high-efficiency, high-density power system solutions, and their supplies are often found in Mil/Aero and other demanding applications.
EE: Nice to talk to you again, Robert. When it comes to power, people forget about it. It's like forest and trees, like green and grass. With no electricity. There's no electronics, right?
Robert Gendron: Correct. You got it.
EE: What are your thoughts about power being in some ways considered low man on the totem pole and yet, like the bottom of the totem pole, the whole thing would fall over if they weren't there on the bottom holding it all up.
Gendron: Well it is. We've seen a shift where power has always been the neglected child, as we say, an afterthought in design, the last thing typically incorporated into a system, where today power is actually on the opposite end. It is in the definition stage, because power is defining many systems as far as the maximum performance that can be achieved or the form factor that can be achieved. So power has definitely shifted in performance over the last... Definitely over the last five years, but a clear trend over easily the last decade.
EE: That's an excellent point to make, because in the before times, as it were, if you were lucky, they would draw a square on the circuit board and say, "Put power there." Now Vicor is known for making some of the best power supplies available. But the bottom line is that power's role has changed, and now power is the first thing a designer thinks about now instead of the last. How do you see the industry taking that?
Gendron: I think the challenge right now in the industry is there is more and more usage of batteries. Again, we're getting away from an engineer having the luxury of having an AC silver box with 3, 5, or 12 Volts available for whatever system they're designing, or being able to buy a wall wart, wall transformer, and then use that to supply their system. What we're talking about today is batteries in robotics, mobile robotics that are not 12 Volts, not 24, but are pushing higher and higher voltages. 100 Volts and such.
In automobiles, which is the most dramatic example, we've gone from 6 Volts in the, what was it, late '50s, I think we transitioned to 12 Volts. Now we see the adoption of 48 Volts, and with EV, we are at 400 and 800 Volts. So in one vehicle today, you can have 800-, 400-, 48-, and 12-Volt buses running around. That multiplicity of bus voltages has never been seen before in a vehicle, or any sort of mobile system.
EE: And Robert, not only the number of conversions, but the magnitude of conversion. I mean, we're talking about shifts of two orders of magnitude.
Gendron: You're right. One of the leading problems right now, our challenges in the industry is converting 800 Volts to 400, or 400 up to 800. And this deals with the compatibility of charger stations and the battery and/or the the battery type, or the battery charging type, that is we're talking about is fast charging. The best example is the Porsche EV, which offers fast charging at 800 Volts. If you're in the U.S., we have pretty much 400-Volt chargers, so you need a converter that can bring 400 to 800 Volts. It's very challenging. And we're not talking about a 1000-Watt converter. We're talking 50 to 100 Kilowatts of power needed on the vehicle, to provide this sort of conversion.
When we look at power, it really comes down to the thermal challenge. How you can manage the heat dissipated from the power conversion. How do you improve upon thermals? Improve on thermals by approving efficiency. But efficiency just doesn't come from the power components used, the type of MOSFET, et cetera. It starts with the foundation of a high efficiency, low thermal, low-heat-generated type design.
It starts with the topology use. There are many switching topologies out there for converting power, but it starts with that. Then, yes, next are the components. Then what's critical is the packaging. If you cannot package effectively, you cannot cool the product. And again, this is what it all goes back to, is managing the thermals during these conversion processes.
EE: Power management is thermal management. That's a two-pronged approach today, right? You've got improved topologies, but you also have improved materials. Literally better semiconductors.
Gendron: Of course wide-bandgap is in the news. It has some very good benefits to it. There's been improvements in ferrite material, so this helps in the magnetics. There has been an obviously improvements even on the IC side, helping us with our controllers and making our controllers operate to higher and higher speeds. So we've seen, again, improvements across the board, even... Not to leave it out, even capacitors. Capacitors have improved tremendously over the last five years.
EE: Well, they're being forced to, aren't they? Because just like you can't put regular tires on a car with a supercharger and twice the horsepower of the factory vehicle, you have to put better tires on, but that means you need better bolts on the wheels, and better drive shaft possibly, and better... It becomes a cascading cycle, upwards and downwards. Once you put a superior component in the chain, you got to improve all the links.
Gendron: That's correct. It all pushes downstream. I mean it starts from the ... Let's say, for example in a robotic system or in a car system, there's a desired form factor needed, and it just pushes down from there. But yes, it goes all the way down, literally down to the pressure put on the, let's say the resistor manufacturers that are out there.
EE: So let's look at it through your perspective, because we're an evaluation and test publication, and we hear a lot from the power test people, but the other side of the coin is you're the power systems manufacturer. What are your thoughts about the challenges for engineers to test and qualify these newer systems?
Gendron: Well, one aspect is literally having a bench set up where you can evaluate a system. As I mentioned, a full system, let's say a converter in an electric vehicle, it could be easily 50 Kilowatts. That's a challenge to operate that on a bench or truly in a demonstration environment versus, let's say, in a vehicle.
So typical practice is an engineer would take a much smaller slice of the power and evaluate that. Let's say two of the primary converters running in parallel, and then try to extrapolate from that. Even there there's challenges. Today, you look at our current benches that we have, and again, that our customers are having, we have a water chiller, we have three-phase power coming down to support 800-Volt supplies. So the bench setup required has dramatically changed. And not just for high voltage, high power, but also on the other extreme.
If you go to our our point-of-load products, we're pulling 1000 Amps out of a voltage regulator at less than 1 Volt. This is a challenge in developing a test setup where you can load it correctly with... In some cases you want to use electronic loads. How do you pull 1000 Amps at a .9, .8 Volts? We have some applications at .5 Volts. And again, this challenges any traditional bench setup in every way.
EE: So let's put this into a little bit of perspective. Name something in one of your product lines targeting the autonomous vehicle or automotive or robotics space, and some of the challenges you have encountered with your customers in them implementing your solution into theirs.
Gendron: If we talk about the automotive space, the biggest challenge for manufacturers has been dealing with a system in a chip, or what we call our power module. It's a much higher level of integration typically than what's been seen in the automotive market. It's a little bit of a learning curve to deal with this power module, where in the past they had the visibility, let's say, to the inside, or a PCB, a discreet converter where they could see the magnetics and all.
So it's a psychological mindset of, again, using this module versus a bag of parts, which, again, being able to see things is always nice, but at the end of the day, clearly, with the density, the thermal challenges in place, higher integration is required, so like most industries, higher levels of integrative power are being adopted. And this is what the automotive industry is seeing right now. Again, it's a massive shift from what they've used in the past when they look at one of our power modules.
