The electric motor of an electric vehicle is an active load, and its speed range is very wide, and it needs to be accelerated and decelerated frequently during driving. The working conditions are more complicated than the general speed control system. Therefore, its drive system is the key to determining the performance of electric vehicles. Where.

With the development of electric vehicles, higher requirements are put forward for power electronic power drive systems, that is, lighter, more compact, more efficient, and more reliable.

Commonly used semiconductor materials, especially chips such as processors and memories in various electronic products, are usually manufactured based on silicon crystals (single crystal silicon or polysilicon). In fact, there is a class of semiconductors based on compound crystals, and SiC (silicon carbide) semiconductors are one of them.

Due to the difference in material properties compared to silicon-based semiconductors, SiC (silicon carbide) semiconductors have better high-frequency, high-power, and high-radiation performance than silicon-based semiconductors.

Silicon carbide is also called gold steel grit or refractory grit. Silicon carbide is made from raw materials such as quartz sand, petroleum coke (or coal coke), sawdust (salt is needed to produce green silicon carbide) and other raw materials, which are smelted at high temperature in a resistance furnace.

At present, the industrial production of silicon carbide in my country is divided into black silicon carbide and green silicon carbide, both of which are hexagonal crystals, with a specific gravity of 3.20-3.25, and a microhardness of 2840-3320kg/mm.

Black silicon carbide is made of quartz sand, petroleum coke and high-quality silica as the main raw materials, which are smelted at high temperature in a resistance furnace. Its hardness is between corundum and diamond, its mechanical strength is higher than corundum, and it is brittle and sharp.

Green silicon carbide is made from petroleum coke and high-quality silica as the main raw materials, adding salt as an additive, and smelted at high temperature in a resistance furnace. Its hardness is between corundum and diamond, and its mechanical strength is higher than that of corundum.