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Silicon steel for electric vehicles

Time : 2017-07-18 Hits : 2017-07-18

When selecting silicon steel sheets for stator and rotor cores of motor, low-loss and high-performance silicon steel sheets should be selected. The thickness of silicon steel sheets has a great influence on iron loss. The insulation materials of silicon steel sheets for special electric vehicle motors should have excellent mechanical properties. Vacuum pressure dipping and solvent-free resin can be used for insulation treatment to improve the insulation effect of motor. At the same time, it adapts to the environment of high temperature and frequency conversion.

The core material of electric vehicle driving motor is mainly non-oriented silicon steel sheet (cold-rolled electrical steel), which is a special material for driving motor cores of electric/hybrid electric vehicles (HEV) and electric vehicles (EV). Its performance and quality directly affect automobile performance. Non-oriented electrical steel for electric vehicle traction motor has higher performance requirements and higher iron loss of electrical steel at high frequency. The magnetic induction intensity of electrical steel sheet at high frequency is also required to be higher. In different stages of motor production, a series of processing and fastening operations such as fastening of silicon steel sheet laminated core, hot sleeve and pressure assembly molding, etc.

Punching/shearing has the greatest influence on the performance of silicon steel sheet. Under normal circumstances, the iron loss of motor will be greater than the material iron loss measured by Ai Postan experiment, M235—35A; 50W600; 35W250. WISCO, the thinnest non-oriented silicon steel in China, produces 0.18 mm. Thin non-oriented silicon steel is a kind of functional soft magnetic material, which has the advantages of low iron loss, high magnetic permeability, low magnetic noise and corresponding economy under the condition of medium and high frequency excitation. WISCO produces 0.23MM; 0.27MM; 0.3MM, HIB steel.

In order to meet the development trend of miniaturization and miniaturization of electric vehicle drive motors and meet the audience of downstream automobile manufacturers, the standard thickness specification range is determined, and cold-rolled non-oriented electrical steel products of 0.2MM, 0.27MM, 0.3MM and 0.35MM are adopted for electric vehicle manufacturers:

1.When the car starts and accelerates, it has high torque and high magnetic induction of silicon steel;

2.High speed corresponds to low iron loss of high-efficiency silicon steel running at high frequency;

3.The narrow space in the car requires the motor to be small and lightweight, and the iron loss and magnetic induction of silicon steel at high frequency are low;

4.Domestic mainstream production of Baosteel and Wuhan Iron and Steel; With the thinning of plate thickness, the iron loss of P10/400 decreases gradually. The national standard brand characteristic character "D" is non-oriented silicon steel for electric vehicles, and "G" is high magnetic induction; The number in front of the characteristic character is 100 times of the nominal material, and the number behind the characteristic character is 100 times of the iron loss of the material, which is expressed in W/KG. Example: 35D1900: expressed as 0.35MM, which is 19W/KG when the total iron loss is P10/400; P10/400 means frequency 400HZ; The magnetic induction intensity (magnetic flux density) is 1.0 T (Tesla), and the magnetic induction intensity is expressed by B. 

For example, B50 indicates that the magnetic induction intensity is 5000 A/m.