Appling Anti-Eddy Current Magnets to improve the High-Speed Motors

Introduction:

For aerospace, automotive, or industrial automation, the efficiency of high-speed motors is very important. However, high speed always results in higheddy currents and then result in energy losses and overheating, which impacts motor performance over time.

That’s whyanti-eddy current magnetshave become important. These magnets help control eddy currents, keeping motors heat and running more efficiently—especially in magnetic bearing motors and air bearing motors. In this article, we’ll explain how this technology works and why the products of“MagnetPower” are particularly well-suited, thanks to their high resistivity and low heat generation.

1. The Eddy Currents

Eddy currents were introduced by “MagnetPower” in former news ).

In high-speed motors, like those used in aerospace or compressors (Line speed ≥ 200m/s) , eddy currents can become a big problem. They form inside the rotors and stators as the magnetic field changes rapidly.

Eddy currents aren’t just a minor inconvenience; they can reduce motor efficiency and can even cause damage over time. Shown al follows:

• Excess Heat: Eddy currents generate heat, which puts extra stress on motor parts. For example, the Irreversible magnetic loss of permanent magnets NdFeB or SmCo always happen due to high temperature.
• Energy Loss: the efficiency of the motor was decreased because the energy that could power the motor is wasted in creating these eddy currents.

2. How Anti-Eddy Current magnets Help

Anti-eddy current magnets are designed to tackle this issue head-on. By limiting how and where eddy currents form, they ensure that the motor runs more efficiently and stays cooler.  One effective way to block eddy currents is to produce the magnets in lamination structure. This method can break the eddy current path, and then prevents large, circulating currents from forming.

3. Why MagnetPower Tech’s Assemblies Are Ideal for High-Speed Motors

Now, let’s dive into the specific advantages ofMagnetPower ’s anti-eddy current assemblies. These assemblies are perfect for magnetic bearing motors and air bearing motors, offering a combination of high resistivity, low heat generation, and increased motor lifespan.

3.1 High Resistivity = Maximum Efficiency

The anti-eddy current magnets developed by “Magnet Power” is to use insulating glue between layers of split magnets, they increase the electrical resistance, above 2MΩ·cm. It is efficient to break the eddy current path.  Therefore, the heat is not easy to be generated.  This is particularly important in magnetic bearing motors. By cutting down on heat, MagnetPower’s magnets ensure that motors keep running smoothly at high speeds without the risk of overheating. It’s the same forair bearing motors—lower heat keeps the air gap between the rotor and stator stable, which is the key point for precision.

Fig1 the anti-eddy current magnets produced by Magnet Power

3.2 High magnetic flux

The magnets are manufactured with a thickness of 1mm and feature a very thin insulation layer of 0.03mm.  This keeps the volume of glue small and the volume of magnets is as big as possible.

3.3 low cost

This process also lowers coercivity demands and costs while enhancing thermal stability, Especially for NdFeB magnets.  If the temperature of rotor can be reduced from 180℃ to 100 ℃, The grade of magnets can be changed from EH to SH. This means the cost of the magnets can be reduced by half.

4. How MagnetPower’s magnets perform in High-Speed Motors

Let’s look at the behavior of MagnetPower ‘s anti-eddy current magnets in magnetic bearing motors and air bearing motors.

4.1 Magnetic Bearing Motors: Stability at High Speed

In magnetic bearing motors, magnetic bearing keep the rotor suspended, allowing it to rotate without touching any other parts. But due to high power (over than 200kW) and high speed (over than 150m/s, or over 25000RPM), the eddy current is not easy to control.  Fig.2 shows a rotor with a speed of 30000RPM.  Because of the excessive eddy current loss, huge heat was generated, causing the rotor to experience a high temperature of more than 500°C.  

MagnetPower’s magnets help prevent this by minimizing eddy current formation. The temperature of the improved rotor did not exceed 200℃ in the same operating condition.3

Fig.2 a rotor after test with a speed of 30000RPM .

4.2 Air Bearing Motors: Precision at High Speed

Air bearing motors use a thin film of air generate by high speed rotation to support the rotor. These motors are designed to operate at very high speeds, even up to 200,000RPM, with incredible precision. However, eddy currents can mess with that precision by generating excess heat and interfering with the air gap.

With MagnetPower’s magnets, eddy currents are reduced, which means the motor stays cooler and maintains the precise air gap needed for high-performance applications like Hydrogen fuel cell compressor and blower.

Conclusion

When it comes to high-speed motors, reducing energy losses and controlling heat generation are key to improving performance and extending the lifespan of your equipment. That’s where MagnetPower’s anti-eddy current magnets come in.

Thanks to the use of high-resistivity materials, smart designs like segmentation and lamination, and a focus on reducing eddy currents, these assemblies help motors run cooler, more efficiently, and for longer. Whether in magnetic bearing motors, air bearing motors, or other high-speed applications, MagnetPower is pushing the boundaries of what’s possible in motor efficiency and reliability.