ZeroAvia Introduces

ZeroAvia Introduces: Mike

Hi, I am Mike. I'm an electrical integration engineer here at ZeroAvia, and at ZeroAvia we're building the world's largest and most powerful hydrogen electric aviation powertrain. And that means that we're using hydrogen to run through a hydrogen fuel cell, which powers an electric motor, which then spins the propeller and pushes the plane through the air. Today I'd like to talk to you about electric motors specifically.

An electrical motor is just a machine that converts electrical energy into mechanical rotation. And motors come in so many different types and sizes. They come almost microscopic, like the ones which might drive the buzzer in your smartphone, to truly enormous and powerful, like the sort of motor that runs your electric car, or like we're developing to drive an electric powered airplane. All motors are driven based on one fundamental principle, and that's this relationship between the flow of current through a conductor and magnetism.

And essentially, if there is a flow of current through a conductor, this flow induces a magnetic field around that conductor. And this means that we can control the strength and direction of a magnetic field by controlling the amount and direction of current that flows through a conductor. Conversely, we can also induce current in a conductor by passing a magnetic field through that conductor. So we use this principle to drive the inner workings of an electrical motor.

Now, there's a bewildering variety of electric motors out there. We might find stepper motors in robotic arms. Brushless DC motors are very popular currently in drones. AC induction motors you find in your kitchen, in the refrigerator, or perhaps in the furnace in your house.

Brushed DC motors are simpler and they tend to be in toys and even power tools of various types. But EVs, so electric vehicles, tend to use a type of motor called a permanent magnet synchronous motor, and that's also the type of motor that we're developing for our electric powertrain here at ZeroAvia. Now, like the name might imply, permanent magnet synchronous motors have permanent magnets, and these magnets are really similar to the ones that you might find stuck to your fridge or perhaps to the whiteboard in your office at work. I've actually stolen two magnets from my colleague's whiteboard here at work.

And here they are now. Magnets have two poles, and these two poles are north or south. Think of them as positive or negative as well. And as we all sort of know, positive and negative poles attract each other.

And if the poles are the same, then they repel each other. So if you see here, they just stick together. And if I rotate one of them here, you can feel actually the one hand being pulled around in a circle by the other one. Now, this fundamental idea is precisely the idea that is behind permanent magnet synchronous motors.

Now, while here I've got two magnets, in a PMSM we actually replace one of these magnets with a ring of electromagnets. Now, as I was mentioning before, the strength of the magnetic field and its polarity, which is created by these electromagnets, can be controlled by the current that we push through the coils of these magnets. Now, with a very clever and sophisticated control scheme, we can actually rotate this magnetic field around the ring that we build around our single permanent magnet here. And so if you can imagine that magnetic field as it is rotated by the electromagnets around it pulls this central magnet around it as well.

And so this is exactly the principle behind the permanent magnets that are on the rotor of a PMSM motor. And this is a simplified version of what we are developing here to put in aircraft. Now, why are we doing this for aircraft? Certainly there are planes out there and they fly very well with combustion engines.

And there are a couple of reasons why we want to do this. A lot of these reasons have to do with the fundamental advantages that we get by using electricity to drive a motor rather than burning things. First and most obvious is the fact that we don't have to burn anything, so there's no pollution, there's no carbon dioxide or other pollutants that might come out of the back of an aircraft engine, a typical aircraft engine that you can see crossing the sky or at any airport that you might go to. In addition, if you've ever looked in the traditional transmission of a car, of a combustion car, you'll see an incredibly complex machine with lots and lots of gears and all sorts of actuators.

Now, if you've ever opened up the motor of an EV, an electric car, you'll see that typically there's only one set of gears. So no real transmission in the traditional sense. This simplicity also applies to electric aircraft. And there we can either have the electric motor attached to a single reduction gear, and then that spins the propeller, or sometimes we can even mount the propeller directly to the shaft that goes through the centre of the motor.

So this is a big simplification from typical aircraft motors and especially piston driven aircraft. The other biggest advantage that you get from using electric motors is their inherent efficiency. So in a typical combustion engine, your efficiency, the actual energy that you get out of a motor as opposed to the energy that you put into it, is maybe between 30 and 40%. You can see this if you go to an airport on a cold day, and you look at the airplanes taking off and you'll see the light is actually bent just behind the engine by the heat streaming out of these engines.

And that heat represents, especially at that phase of flight, about 70% of the energy that would be in the fuel. Now an electric motor is typically 90 to above 90% efficient. So you can actually get the same power, the same energy that's actually doing useful work, with much less fuel with an electric motor. So these are a lot of the reasons why it's a fascinating time to be working here at ZeroAvia on the world's most powerful hydrogen electric drivetrain for aviation.

I get to play with powerful electric motors and high voltage and a lot of other things that make electrical engineers like me happy. So thanks for watching, and please check us out at zeroavia.com. Thanks.

ZeroAvia Introduces: Aajay and the Fuel Cell

Hi, I'm Aajay. You may have heard about hydrogen electric engines, thanks to our recent breakthrough flight demonstration. These new systems use fuel cells and electric motors to fly aircraft and can deliver zero emission flights for passengers and cargo. If you want to know how fuel cells can work in aviation, this video is for you.

Firstly, let's cover why fuel cells are so important for the future of truly clean aviation. Aviation is the fastest growing source of greenhouse gas emissions. There are solutions that can help us reduce the carbon emissions from flying aircraft today, but in aviation, that's not good enough. Non-carbon emissions account for an estimated two thirds of the climate impact.

Air pollution impacts of nitrogen oxides and particulate matter are also of growing concern to public health, for those living in and around airports. The solution to these challenges needs to be economically viable for airlines. Fuel cells are two to three times more fuel efficient than combustion engines. Plus the hydrogen electric system will entail lower maintenance costs.

So for all of these reasons, fuel cells and hydrogen are now thought to be the future of aviation and could be operational in up to ATR-class aircraft very soon. So how do fuel cells work in aviation? In our current system, we use proton exchange membrane, PEM fuel cells. Sounds complicated, but fuel cells are not very different from batteries.

Fuel cells generate electricity, use hydrogen as an input and have added benefits of less degradation. Fuel cells don't need to be recharged. This ensures they can run as long as hydrogen is available, and hydrogen refuelling can be done in a few minutes. PEM fuel cells generate electricity through an electrochemical reaction that combines hydrogen and oxygen, and the product is just water.

A catalyst separates hydrogen atoms into protons and electrons, which take different paths to the cathode. Hydrogen protons pass through the membrane while electrons are funnelled off in an external circuit to create a flow of electricity. The byproducts are water vapour and heat. The temperature of water vapour exhaust is nearly 10 times lower than with combustion engines, even making it possible to mitigate the contrail impact.

Thus, the system can be truly zero emission. The electricity we generate from fuel cells is then fed to inverters to power electric motors, which turn the propellers. So what kind of aircraft can be powered using fuel cells? The short answer is all kinds.

We will first deliver our engines powered by fuel cells for up to 20 seat fixed wing or traditional aircraft by 2025, and then up to 80 seat aircraft by 2027. This will include existing aircraft in service where we remove fossil fuel engines and replace them with our zero emission system. But fuel cells can also power a whole new generation of innovative aircraft designs, from novel planes to eVTOL applications. At ZeroAvia, we are working on low temperature PEM fuel cell systems for up to 20 seat aircraft, and also developing our own high temperature PEM fuel cell stacks in-house.

If you want to learn more, we will cover these technologies in our tech deep dive series. So look out for these on our YouTube channel soon.