Photo: UEC Have you ever wondered why humanity is increasingly switching to electric vehicles on earth and even underground, but we still fly through the air, burning tons of kerosene? Why, when there are more and more electric cars, trams, trolleybuses, electric scooters, subways and electric trains around us, do we not see electric planes in the sky? Isn't it strange that electric motors, which are much more efficient than thermal ones, still do not allow us to save on the cost of flights? After all, everyone knows that the price of fuel is one of the reasons for the high price of plane tickets.
We can say that the answer is obvious. To date, we do not have batteries of sufficient power and capacity corresponding to dimensional characteristics for use in aviation. A small drone with a minimal payload and a fairly short flight time is one thing, but a passenger plane is another. It is difficult to even guess how much space the batteries will take, for example, in the Russian SSJ-100 airliner to ensure flight over its standard distance. It is likely that there will be no room left for passengers, if it can take off at all stuffed to the brim with rather heavy batteries.
A mock-up of a hybrid power plant for aviation
Precisely because fuel for turbojet engines (turbojet engines) takes up significantly less space, we still have to put up with its high cost, relatively low engine efficiency, harmful emissions, noise and difficult maintenance.
It is logical to conclude that, until new compact and capacious energy sources are invented, electric traction will be used only in small aircraft, where the requirements for payload, passenger capacity and flight range are much lower. In fact, this is not quite true.
Automakers have faced similar problems. For quite a long time, the high cost and low battery capacity did not allow the production of electric vehicles capable of traveling a distance comparable to cars powered by internal combustion engines. And this is despite the fact that the weight of car batteries is a much less significant parameter for wheeled vehicles than for airplanes.
But it is only in recent years that automakers have begun to pay more attention to one hundred percent "electric trains". This has been led by the development of new batteries, which are becoming more compact and capacious. Nevertheless, they are still too big and heavy for aviation.
Hybrid power plant based on VK-650V
And a little earlier, the introduction of hybrid cars allowed to increase the efficiency of cars by significantly reducing fuel consumption and thereby simultaneously reducing harmful emissions. Today, "hybrids" are quite an ordinary technology in the automotive industry.
Aviation appreciated this experience and decided that increased attention should be paid to the creation of hybrid power plants (HSU). To date, all leading aircraft engine manufacturers are working in this area. The list includes such giants as the American Pratt & Whitney and General Electric, the English Rolls-Royce, the French Safran and, of course, the Russian United Engine Corporation.
Despite the different characteristics of the power plants being developed, all GCS have a common feature − the symbiosis of a thermal and electric motor. This summer, UEC presented at the Technoprom-2023 international forum a 500 kW hybrid powerplant demonstrator based on the promising VK-650V helicopter engine.
Let's look at his example of how a hybrid power plant works in aviation. The VK-650V turboshaft engine, operating at optimal mode, is connected to a generator, and that is connected to the batteries and electric motors of the aircraft through a special electrical system. In cruising flight mode, electric motors are powered only by a generator, and the excess energy is used to charge the batteries. During takeoff and landing, i.e. in the mode of increased engine load, additional battery power is connected.
The constant operation of the VK-650V will ensure high fuel efficiency, increase the resource and ensure stable power generation. The batteries will close short-term increases in the power of electric motors in flight modes and, importantly, will not allow the electric motors to "stall" when the turboshaft fails and instantly increase the electric power. All these innovations will ensure cost-effectiveness and safety of flights.
We just have to wait until we can see the first full-fledged aircraft from the GSU. This technology has great potential applications – from drones to passenger planes and helicopters. Of course, GSU is unlikely to be able to immediately displace other power plants from aviation. But already today, their capabilities attract developers from different countries.