Problems such as exhaust pollution and oil safety have prompted new energy vehicles to become the mainstream of future motor vehicles, and high-grade non-oriented electrical steel, as an important soft magnetic material, is widely used in high-end home appliances, new energy vehicle drive motors and efficient industrial motors and other fields.

In previous studies, the influence of various factors on motor noise has been widely explored, such as the influence of pulse width modulation current on the acoustic noise behavior of internal permanent magnet synchronous motor drivers;

On the other hand, in inverter-controlled switching operations, secondary loops are created in the hysteresis curve, which increases core losses. Although there are some researches on the magnetic properties of motor with inverter excitation at home and abroad, the influence of iron core size on the magnetic properties of motor is still unclear.

The motor iron core is usually made of non-oriented electrical steel plate, common plate thickness of 0.5 mm and 0.35 mm. This material is chosen because the high-speed rotation of the motor is related to the high frequency of the magnetic field in the iron core, and the iron loss of the electrical steel plate will increase with the increase of frequency.

The global motor iron core market currently mainly uses advanced materials such as electrical steel. Electrical steel has the advantages of low core loss, high permeability and high strength at high frequencies.

A dry-type transformer is a transformer that does not contain flammable or flammable liquids in the insulating material. Its insulation system usually uses solid insulating materials, such as epoxy resin or porcelain tiles. There are three reasons why dry transformers usually place pebbles at their bottom.

There are a variety of sizes on the chip, which can be classified as "internal size" and "matching size". Internal dimensions such as slot size, ventilation hole, marking slot and magnetic pole punching hole size, etc., generally use H10, higher accuracy level is not necessary, because after stamping, the error caused by inside and out is far greater than the error of the punching film itself.

According to the requirements of Q/GDW11744-2017 National Grid enterprise standard, the construction of UHV power grid project will mainly use high magnetic induction oriented electrical steel (HiB), The grades are 23QG080, 23QG085, 23QG090, 27QG085, 27QG090, 27QG095, 27QG100, 30QG100, or higher.