Mahle, a German auto parts company, has developed high-efficiency electric motors for EVs, and it is not expected that there will be pressure on the supply and demand of rare earths.
Unlike internal combustion engines, the basic structure and working principle of electric motors is surprisingly simple. I think many people have played with “four-wheel drive” when they were young. There is an electric motor in it.
The working principle of the motor is that the magnetic field acts on the force of the current to make the motor rotate. A motor is a device that converts electrical energy into mechanical energy. It uses a energized coil to generate a rotating magnetic field and acts on the rotor to form a magnetoelectric force rotation torque. The motor is easy to use, reliable in operation, low in price and firm in structure.
So many things in our life that can rotate, such as hair dryers, vacuum cleaners, etc., have motors.
The motor in a pure electric vehicle is relatively larger and more complicated, but the basic principle is the same.
The material needed to transmit force in the motor, and the material that conducts electricity from the battery is the copper coil inside the motor. The material that forms the magnetic field is a magnet. These are also the two most basic materials that make up a motor.
In the past, the magnets used in electric motors were mainly permanent magnets made of iron, but the problem is that the strength of the magnetic field is limited. So if you shrink the motor down to the size it plugs into a smartphone today, you won’t get the magnetic force you need.
However, in the 1980s, a new type of permanent magnet appeared, called a “neodymium magnet”. Neodymium magnets are about twice as strong as conventional magnets. As a result, it is used in earphones and headsets that are smaller and more powerful than smartphones. In addition, it is not difficult to find “neodymium magnets” in our daily life. Now, some speakers, induction cookers, and mobile phones in our lives contain “neodymium magnets”.
The reason EVs start up so quickly today is due to “neodymium magnets” that can dramatically improve the size or output of the motor. However, after entering the 21st century, a new problem has arisen due to the use of rare earths in neodymium magnets. Most of the rare earth resources are in China. According to statistics, about 97% of the world’s rare earth magnet raw materials are supplied by China. At present, the export of this resource has been strictly restricted.
After developing neodymium magnets, scientists tried and failed to develop smaller, stronger, and even cheaper magnets. Since China controls the supply of various rare metals and rare earths, some analysts believe that the price of electric vehicles will not drop as expected.
Recently, however, the German automotive technology and parts development company “Mahle” has successfully developed a new type of motor that does not contain rare earth elements at all. The developed motor contains no magnets at all.
This approach to motors is known as an “induction motor” and it creates a magnetic field by passing current through a stator instead of magnets through which current can flow. At this time, when the rotor is affected by the magnetic field, it will induce electromotive potential energy, and the two interact to generate rotational force.
Simply put, if the magnetic field is permanently generated by wrapping the motor with permanent magnets, then the method is to replace the permanent magnets with electromagnets. This method has many advantages, the principle of operation is simple, and it is very durable. Most importantly, there is little reduction in heat generation efficiency, and one of the disadvantages of neodymium magnets is that their performance decreases when high heat is generated.
But it also has disadvantages, since the current continues to flow between the stator and rotor, the heat is very serious. Of course, it is possible to make good use of the heat generated by harvesting and use it as a car interior heater. Beyond that, there are several downsides. But MAHLE announced that he had successfully developed a non-magnetic motor that made up for the shortcomings of the induction motor.
MAHLE has two major advantages in its newly developed magnetless motor. One is not affected by the instability of rare earth supply and demand. As mentioned above, most of the rare earth metals used in permanent magnets are currently supplied by China, but non-magnet motors are not affected by the pressure of rare earth supply. In addition, since rare earth materials are not used, it can be supplied at a lower price.
The other is that it shows very good efficiency, with motors commonly used in electric vehicles having an efficiency of around 70-95%. In other words, if you provide 100% of the power, you can provide at most 95% of the output. However, in this process, due to loss factors such as iron loss, output loss is inevitable.
However, Mahler is said to be more than 95% efficient in most cases and as high as 96% in some cases. While exact numbers haven’t been announced, expect a slight increase in range compared to the previous model.
Finally, MAHLE explained that the developed magnetic-free motor can not only be used in ordinary passenger electric vehicles, but also can be used in commercial vehicles through amplification. MAHLE said that he has started mass production research, and he firmly believes that once the development of the new motor is completed, he will be able to provide more stable, lower cost and higher efficiency motors.
If this technology is completed, perhaps MAHLE’s advanced electric motor technology can become a new starting point for better electric vehicle technology.
Post time: Feb-04-2023