The role of SIC power devices in automotive electric drive systems

The saying that a car has three major parts has always been deeply rooted in people's minds, from the well-known engine, gearbox, and chassis of fuel vehicles to the batteries, motors, and electronic controls of new energy vehicles.

In fact, this is a very general term. We know that the power battery contains complex structures such as battery cells, electrolytes, positive and negative electrode materials, etc., so the motor is no exception.

As the requirements for driving range and fast charging of automobiles become higher and higher, the electric drive system is actually composed of multiple modules. The current mainstream technology is the three-in-one drive motor, motor controller , and reducer.

Therefore, the integration and miniaturization of hardware are permeated in all aspects. Taking up less space and improving efficiency are the eternal pursuits of car companies!

We already know that electric vehicles are powered by motors, but how is this power generated? It must be achieved through an electronic control unit (motor controller). The electric vehicle motor controller drives the motor to work by modulating the output sine wave through an inverter bridge.

This electronic control unit (motor controller) is generally composed of a power distribution circuit, an auxiliary power supply , a drive circuit power device ( IGBT ), a DSP circuit, a structure and a cooling system.

Circuit knowledge Very complex, the most important and core of which is the power device, that is, IGBT or SiC power module . At present, BYD e-platform 3.0 electronic control unit uses a new generation of SiC electronic control, the power density is increased by nearly 30%, and the maximum efficiency of the electronic control is 99.7%.

Since it is the core of the core, it can of course be replaced with equal components. The power device is the core of the drive motor assembly.

This seemingly small key module was previously mostly in the hands of companies such as Infineon . This independently developed and manufactured high-performance silicon carbide power module is one of the few SiC three-phase full-bridge modules in China that have been installed in large quantities in motor drive controllers .

SiC power modules have stronger performance and relatively higher costs. Currently, BYD SiC modules are mainly used in motor drive controllers for high-end models, and are used in Han EV, which has greatly improved performance. This has injected a shot in the arm for the development of the domestic SiC industry chain and laid the foundation for the large-scale automotive use of silicon carbide!

At present, the main R&D institutions of silicon carbide IGBT include Cree, Japan National Institute of Advanced Industrial Science and Technology, etc. Domestic research institutions include the 55th Institute of China Electronics Technology Group Corporation, the Semiconductor Institute of the Chinese Academy of Sciences, Xidian University and Beijing Smart Energy Research Institute, etc.