Podcast: Megawatt Motors For Electric Flight

In this episode, we discuss the megawatt electric motor design from MIT that aims to address a critical and unspoken shortcoming regarding the future of electric flight: generating enough thrust. 

This podcast is sponsored by Mouser Electronics.      

(3:46) - Megawatt electrical motor designed by MIT engineers could help electrify aviation

This episode was brought to you by Mouser, our favorite place to get electronics parts for any project, whether it be a hobby at home or a prototype for work. Click HERE to check out the article on autonomous luggage!

Transcript

What's going on, folks? Welcome back to the NextByte podcast. And in this one, we're going to be talking about electric flight. More specifically how MIT is tackling one of the most ignored problems when it comes to electric flight. So, if you're interested in all things, electrification, or aerospace, then buckle up, literally because this one is for you. Let's take off.

I'm Daniel, and I'm Farbod. And this is the NextByte Podcast. Every week, we explore interesting and impactful tech and engineering content from Wevolver.com and deliver it to you in bite sized episodes that are easy to understand, regardless of your background.

Farbod: Alright, folks, welcome aboard the NextByte flight before we take off a quick word from today's sponsor Mouser electronics you guys know we love Mouser, right? And again, before taking off today, what do we got to do, we got to go to the airport. Now what happens at the airport, you got to bring your luggage you got to check it in. Now, I don't know if you've noticed. But the world of robotics has been taken off like crazy. So, we're finding robotic stuff in our everyday products. And what better way than to integrate robotics into your suitcases. And that's what today's Mauser technical resource is about. It's about how all this technology is finding its way into our suitcases which by the way, seven-year-old Farbod would have freaking loved riding around suitcases that was like my favorite pastime. And now what's happening. Now it's all the little seven-year-old Farbod across the world, and seven-year-old Daniels can now get on, I don't know, a full-size suitcase and ride around until it's time to board or check in your bag.

Daniel: Well, and it's not just that right, you don't have to sit on it and ride around. Because falling out the ability like to use, they call these AMRs autonomous mobile robots basically use a lot of the same technology that exists in self-driving for like autonomous cars, like sensor fusion, computer vision, proximity sensors, microcontrollers, etc. You make a suitcase that will follow you around the airport, imagine never having to lug your luggage, right that's in the name, lugging it around, you never have to lug it anymore. You know your bag with all your goodies, you never know it goes on attended can't get stolen, it just follows you around the airport. And you don't have to, like spend all the time and effort carrying it sounds like an awesome future sounds like the future of air travel, which is what we're talking about today, right?

Farbod: And if you're anxious about being late to your flight, and all that jazz, that usually comes with you know, travel like I am, it totally makes sense to have something like this. Because now as you try to put your shoe on after you do the security check, you're not worried about lugging your stuff around in one hand and then your bag in the other and pulling your friends forward. That's just one less thing on your mind. It's just convenience in your life. So, it's a cool, it's a cool article, it just goes into this technology and benefits of it, like Dan said, how much it carries over and the similarities between this and autonomous vehicles. So, if either of those two topics are interesting, you should definitely check them out.

Daniel: I will say like, as an engineer, as a geek trying to understand this, it's super valuable to me that Mouser even has like schematics illustrating exactly how all these components are going to work together in an autonomous mobile robot to build suitcases. Maybe, if you're listening to this, and you're like, Dang, this is a really good idea. I'd love to build one. You've got the makings for it right there. Mouser already tells you what types of components you'll need already gives you a schematic for a basic outline of how it will work. I'm here for it. Mouser has given engineers the weapons they need to be dangerous.

Farbod: You know, we talked about secret sauces all the time. Well, Mouser is the one that brings all the ingredients together for the secret sauce to happen.

Daniel: Yeah. All right, we've got a link to in the show notes, right. We do, check it out if they're interested.

Farbod: Definitely. Now that we got our baggage checked in, let's talk about today's flight. And we're going to be making a quick pitstop at MIT to talk about how they're trying to crack the code for making electric flight happen. Now, we have done a couple episodes on this podcast about electric flight, right? I think even one of our very early ones was about electric flight. What was it like, the German Aerospace Center, right, something like that. They were, they were looking at fuel cells. A big portion of this discussion that comes to electric flight has been around the fact that we're trying to get to carbon neutral by 2050. That's the world's goal. And these airline travel, like the planes are contributing a non-trivial amount of the carbon emissions. So, if we can make them electric, it's great. But a lot of the conversation has been around what kind of energy source are we going to use, or we're going to put on batteries. Batteries are difficult because they weigh a lot. And once we've used the energy, like there's deadweight to hang on, then like we just said, German Aerospace Center. They've been talking about fuel cells, but.

Daniel: That was episode 8, by the way. If someone's willing to want to throw back 120 Something episodes, you can listen to it. We talked about fuel cell powered airplanes, but I'm with you right out of the bat a lot. The debates been over batteries versus fuel cells, or do we make hybrids? All of those assume that we've got an electric motor that we can use, right regardless of what the propulsion, the power sources and assumes that you've got an electrical motor powerful enough, light enough, decent enough from a thermal performance perspective that you can actually have an electrically propelled airplane. That's doesn't actually exist today. It doesn't.

Farbod: And like all these, because there have been prototypes, I think Rolls Royce actually made a prototype airplane that is electric. And it's a single seater, like classic looking turboprop airplane. It's not the commercial type. And I don't think it even flies for that long. So, there's this, like I said, big elephant in the room in terms of like, Alright, you guys are having this discussion about what the energy sources are going to be what the energy storage technique we're going to use is going to be, but what is actually going to do the flying part, what's going to make that happen, and we need some pretty critical breakthroughs to happen here. And there's a problem with electric motors, like the one that's driving your Tesla, or the one in your RC car, whatever. The engineering behind it is actually kind of straightforward, which is one of the benefits of having these electric motors versus an internal combustion engine in your car. There aren't too many moving parts, you have this, this stator that has the magnets, which the with different polarities, that is turning this magnetic rotor, which is typically connected to the wheel of your car from not mistaken. And then you have a heat exchanger, that's as the name implies, is supposed to make sure that nothing is melting down in there, you're offsetting the heat. Keeping it cool, right? That's the general idea. Now as you scale this thing up, and you want more power out of this system, you're going to have to have more of these copper coils, bigger copper coils in the stator. And even in the magnetic rotor, which means you're going to get additional weight, now that you have a bigger system, that's, you know, a lot more current moving through it, you're gonna have to have a better heat management system, which means bigger and more moving parts added onto it. So again, as the energy you want out of it scales, so does the size and so does the weight. And that's a problem for airplanes, we've talked about it again before, when it comes to aerospace applications, weight is a no go like that is the one thing you're trying to minimize. So, it doesn't really make sense to take the approach of what we've been doing with burning, you know, jet fuel, which is just put something big, and we'll call it a day and we'll just put all the fuel in the in the wings and burn it off. No, you have to be kind of pretty conscious when it comes to these things here. Yeah. So, you want to get into what's happening here?

Daniel: Well, I was gonna say is like, you refer to Tesla as an example, right, your model three drive unit, like fundamentally speaking, what we're looking at, in terms of power demand, to like, make a plane fly, versus like to have your, your car drive down the highway, we're gonna need multiple motors in the megawatt scale, probably, to be able to get one of these planes to fly pretty sustainably. And that's kind of like the, the glass ceiling so to speak, that these engineers have been trying to break is can we make an effective megawatt electrical motor, that light enough, that's got good enough thermal performance. And they think that that'll get us in the right ballpark for power output to get like a small medium passenger plane, like a regional jet, or private jet up in the air flying, etc. That's still like, that's six times more power output than the drive unit and a Tesla Model 3, and they're trying to make it lighter and smaller than the front drive unit and a Tesla Model 3. So, it's like, from a technical challenge perspective, they're trying to solve a pretty challenging problem here. They're trying to reduce mass, they're trying to reduce overall footprint in a way that also still allows them to get six times the power output of the Tesla Model 3 front drive unit. It's a sticky problem here that this team from MIT is attacking.

Farbod: Absolutely. And he talked about it, I think there's a much-needed context, which is, you know, what are we actually looking at how big is the problem? You and I, before the episode started, in our notes, we had written down some figures for what is required for some popular aeroplanes to operate. I have the 737 down because that's like a smaller airplane use for regional travel, you have the A380 down, which is like I think the biggest commercial airplane made right now. And if I'm not mistaken, the power required for takeoff is somewhere in the 200-megawatt range, right?

Daniel: 230 megawatts required to get an Airbus A380.

Farbod: And to cruise it's 20-23 megawatts? I think somewhere around that range. Yeah, so the 737 is about 7.2 megawatts of power needed to crews and I'm just gonna scale with your fingers. Let's say it needs 70 to take off. So even at this scale that these folks are working at, like having a one-megawatt motor to drive A turboprop or whatever you would, you would need quite a few of these to take current sized planes off the ground. And that's not a trivial task like, this is a big lift, big lift, like that, you like that, huh? That's, that's a good pump. But now I think it's, it's worth getting into, you know how they're trying to accomplish this task and what kind of progress they've made? Yeah, again, they've kept it pretty simple. All the key components are still the same, there's four critical components, you have the heat exchanger, the stator, the magnetic rotor. And then where there's a lot of innovation happening is the PCBs that they've developed for regulating currents in these copper coils. So, this thing is going to be the magnetic rotor is going to be spinning very, very fast to get the amount of thrust required to take off. And to make sure that that's maximized in terms of power delivery to these magnetic poles, and to limit the amount of heat generated. They have these PCBs that are all interconnected to these different coils, and they're regulating the current draw for every coil, at the various stages of operation. So that's like, one of the big, I don't know, our bowl chilies in their secret sauce, right. And they've also done a pretty good job, I think what the heat exchanger, if I'm not mistaken, it has no moving parts, it's a passive static heat exchanger, that is able to cool down mostly the stator, not the magnetic rotor. And that's completely fine, because all the heavy magnets are typically placed in the stator. Whereas the magnetic rotor is just, it's a more lightweight design. So those are the things that they have going for them. And computationally, they've been able to prove that they are able to get one megawatt of power output from this thing. And individually, they've created every one of these components, tested them and verified that it meets or exceeds their expectation for what the performance shouldn't be.

Daniel: Well, and honestly, what I was looking for here is like some low hanging fruit, something that's easy to explain something for us to have like as an easy takeaway here. The team says, there was basically no silver bullet, right, there was nothing that they could do to any one of those four main components, the rotor, the stator, the heat exchanger, the power electronics, there wasn't one thing that they did to me one of those four components that they were like, that is the reason why we can reach megawatt power output. What they did do though, is they holistically took a look at what traditional technologies exist, what cutting edge technologies exist. And then from a fundamental level, like you said, in simulations, designed each one of those four components with the goal of reaching that one-megawatt power output, so they optimized specifically for power output across the board. That was able to get them to a one-megawatt power output. Again, they specifically designed the rotor, specifically designed the stator, with the copper windings specifically, designed the heat exchanger and the power electronics systems. You know, again, it's 30, custom built circuit boards that are a part of that power electronics system, they didn't skip any detail and getting to where they are today. They're actually a team that's not an electronics-based team. They're a team that focuses a lot on gas turbines. So, they, they know a lot about building engines, they know a lot about designing engines. And I think they took a lot of expertise here with the end purpose in mind to create this motor, or at least this concept for a motor that can crack through this hypothetical glass ceiling of one megawatt power output. Personally, speaking here, I come out of this, and I'm still like, so what right? How big is it? How wide is it? How good is it from a thermal performance perspective? Those were the things that we're talking about as pain points from the beginning. As designed this MIT solution, this electric motor, and then all the power electronics. Each motor is about the size of a check suitcase, weighing less than an adult passenger. So again, we're not talking about something that's huge. We talked about suitcases at the beginning of this episode. Imagine a couple of these suitcases that's what we're looking at from like a size and mass perspective. It seems like they've started to get this again, it's mostly theoretical at this point, but started to get this theoretical design for a motor into a future where we can possibly get more of these motors cracking this one-megawatt barrier, they're light enough to put on a plane, they've got a small enough packaging space that you can put them on the wing of a plane as opposed to having just like one prop in the center of the nose. It sounds compelling to me. Again, I would love to see them do this. I would love to see this get tested. And one of the things that they mentioned that was particularly compelling to me, is they say like, we know that this isn't enough power for these huge commercial jets yet, right? But this is an awesome proof of concept that can hopefully encourage people and like create some breakthroughs for other teams to start developing things and like the two-three-four-five megawatt power range. But they also said we can include this as part of a hybrid powertrain system, which I thought was really interesting. Especially when you're talking about, I think it was the 737-300 was the one that needed only 7.2 megawatts of power needed to cruise. Maybe they could use like, like normal jet fuel to get the jet off the ground. And then once they're at cruising altitude, they can switch over to their electric powertrain system. And cruise, they're at that, you know, lower power demand, maybe that's a future that we could get to, at some point. Or maybe we do it the other way around, we use a really, really light, really, really efficient cruising motor, and then you're able to boost it with some extra power from the electric motors. during takeoff and landing when you need the extra power, I'm not sure. But it was something that was particularly compelling to me is the fact that this could crack open the potential to create hybrid systems because it's one of the first electric motors we talked about in the aerospace realm that has enough power packs enough punch for the weight and the size that it has to bring on board along with it.

Farbod: No, you're spot on. And that's the one thing that really stood out to me too, because, you know, we have this deadline for 2050 to be carbon neutral. And I don't think like even the automotive industry, we're not seeing a switch getting flipped everyone going, EV? It's more of a slow transition like we had hybrids first, then you have plug in hybrids, and even today, you're still seeing advancements in hybrids, plug in hybrids, and EVs. Right. So, it totally makes sense to me that the transition to getting to fully electric flight would be that the prerequisite of it would be something like hybrid flight. And this application of you know, taking off actually requires a whole lot of power. And maybe we can't do that right now. But what if we demonstrate this, this technology and cruising, whereas with these smaller regional, very popular aircrafts, it's totally possible to do. And by the way, you know, a podcast is delivered through an audio medium, we always encourage you guys to check out the article. This one, you definitely should. Daniel mentioned the size of this engine, you should just see it in scale. And it really allows this vision and the efforts that these folks have put into holistically optimize the system, not just for power output. But how do we make everything good, not let it overheat, not be too big, yada, yada, yada. I think visually, it puts it into perspective, I think.

Daniel: And there are photos of everything, right? There are photos of the power electronic systems, you can see all 30 of the circuit boards, you can see the rotor, you can see the stator, you can see the heat exchangers, it's all really compelling. One kind of note I want to leave us on here is like, I think it may feel like it's a potentially like unsatisfying ending to the story, right? That, you know, we haven't built this yet. And even if we do like, we may only be able to use it for private jets, or like midsize reasonable regional jets. I will say, if you're looking from like, where to attack from a carbon emissions perspective, on a per passenger basis, private jets emit 10 to 20 times as much as commercial airliners do from a carbon emissions perspective. So even if we're only ever able to get electric propulsion, up and running, for these regional jets, or for private jets, in the near term, we're actually making a huge dent in the total emissions per passenger, you know, as compared to when we're able to actually get pretty efficient getting to 300 people on a plane, the shared emissions per passenger is actually not that bad on a commercial liner as there is when you've only got one or two people in a private jet.

Farbod: That's a great point. And if I can give a little input to maybe lift the spirits a little bit. In June, they actually the team attended this conference to show just like what this is and get other people's feedback on it. It was called the Electric Aircraft Technology Symposium. So that's a win. And they've actually talked about doing a full assembly of this motor and doing testing of it as a system in the fall. So, we're not too far off from that either. So, two exciting milestones that I think is worth looking forward to. And before we fully wrap up, I'm going to try to do a quick, ELI5 wrap up. Let's do it. When it's stretch, make sure I get it right.

Farbod: All right. So electric flight. It's something we've been talking about for a while, and it's something we need to do because we're trying to go carbon neutral by 2050. Now everyone is talking about energy storage, the energy method, or we're going to use batteries, or we're going to use fuel cells, but no one is talking about the elephant in the room. And that is the motor. How are we going to power this thing? Well, folks at MIT have decided to tackle this challenge. Typically, electric motors. They're big, they're heavy if they need to provide a very high-power output because you have heat exchangers and other components that need to scale with them. Well, these folks have completely flipped the script. They said, what if we optimize the system as a whole? What if we look at every component, the stator, the magnetic rotor, the PCBs, the heat exchangers, and make sure that they are focused on one main thing, and that's being as lightweight as possible, with as much power output as possible. And the result is a system that can generate one megawatt output power. And that might not seem like a lot. But when you think about the fact that a 737, which is one of the most popular aircraft in the world, only needs 7.2 megawatts of power to cruise, and that this thing is as small as a piece of luggage, then it's pretty impressive. Now, this might not be the silver bullet that gets us to full electric flight in the next month or two. But it could be the thing that we need to inspire everyone else to start integrating this technology into their products. Wink, wink, Airbus and Boeing.

Daniel: Yeah, I'm with you, man. And I'm really looking forward to seeing what this team from MIT can achieve. Feels like something and we could potentially do a follow up Episode on in the fall after they build it. Or if there's enough interest, and we're able to make a connection, it'd be awesome to interview someone from the team and learn more about what they're working on.

Farbod: Man, I'd love to, especially in the fall. You guys should invite us out. We'd love to see the testing.

Daniel: Yeah, if you've got connections at MIT or someone from the teams listening, reach out to us. We're super stoked to get on board.

Farbod: Definitely. All right. Is that it? I don't think there's anything else talking about.

Daniel: Just a thank you to our friends in Azerbaijan. Again, we I think we've been in the top like 200 podcasts in Azerbaijan for almost the last month. Thanks to our friends there who've been supporting us for listening. We appreciate you being such a valuable part of the community. We wouldn't do it without everyone, you know, helping us grow the way you guys are.

Farbod: Absolutely. Thank you guys for the love every day, every week, or so many weeks.

Daniel: Yeah, I like, honestly Azerbaijan's quickly climbing my ranks of favourite countries in the world because of this.

Farbod: We're gonna have to visit soon in the NextByte tour.

Daniel: Yeah, I'm with it.

Farbod: Alright, everyone. Thank you so much for listening. And as always, we'll catch you in the next one.

Daniel: Peace.

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That's all for today The NextByte Podcast is produced by Wevolver, and to learn more about the topics with discussed today visit Wevolver.com.

If you enjoyed this episode, please review and subscribe, via Apple podcasts Spotify or one of your favorite platforms. I'm Farbod and I'm Daniel. Thank you for listening and we'll see you in the next episode.

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