Magnetic steel reduction scheme: Exploration and application of segmented magnet and angle diffusion.

At present, as the competition in new energy permanent magnet synchronous motors is becoming increasingly fierce, magnet, as the core material of motors, has its performance and cost directly determining the market competitiveness of motor manufacturers.

How to reduce the content of heavy rare earths in magnet while meeting the performance requirements has become the focus of research for major motor manufacturers.

The following will introduce two ideas for reducing the cost of magnet.

The laminated magnet technology realizes the innovation of the magnet structure by radially dividing the magnet into several sections and then bonding each section together with insulating glue, as described in the following figure.

This design helps to reduce iron losses and improve the efficiency of the motor, and it has been widely used by advanced enterprises such as Tesla at present.

A new idea for the application of laminated magnet technology: using magnets with different coercivities in the laminated structure to achieve the purpose of cost reduction.We know that the four corners of magnet usually exhibit relatively high magnetic flux density, which means that only the magnet on both sides requires a high coercivity. Therefore, an innovative idea has emerged: keep the grades of the magnet on both sides unchanged while reducing the coercivity of the magnet in the middle. This strategy not only helps to maintain the overall performance of the magnet but also significantly reduces costs. However, there are two issues facing the application of laminated magnet:

? Glue cost issue: Due to the use of the glue bonding method, the cost of this technology has increased compared to that of traditional magnet. Whether the decrease in the cost of magnets after reducing the coercivity can cover the increase in the cost of glue? This requires each magnet manufacturer to strengthen its technological capabilities and minimize the amount of glue used as much as possible.

? Motor performance may decline: Due to the independence of the segmented magnet, the magnetic leakage phenomenon is more obvious compared to that of the integral magnetic steel, which may have a certain negative impact on the performance of the motor.