What exactly are IGBTs and replacement silicon carbide?
For a long time, many people think that the key to new energy vehicles is the battery, and even the "three power", the battery is always ranked **, but in fact, the development of new energy vehicles, especially China's new energy vehicles, has room for improvement Yes, it is the drive motor.
。 On December 16, 2018, at the media briefing session of the China Electric Vehicle Hundred People Forum, Academician Ouyang Minggao, Executive Vice Chairman of the China Electric Vehicle Hundred People Association, introduced the "13th Five-Year" New Energy Vehicle Key Project Annual Summary and introduced Regarding the development of new energy vehicle technology, in terms of driving motors, Ouyang Minggao pointed out that silicon carbide will replace IGBT .
Wait, what is IGBT? What is silicon carbide? What is the relationship with the drive motor?
What is IGBT?
Invented in the early 1980s, the IGBT, scientific name Insulated Gate Bipolar Transistor, is the third most representative product in the internationally recognized power electronics technology.
，能决定整车的能源效率;简单点理解，它就是电力电子行业里的“CPU”。 Graphically speaking, IGBT is a superior switch that controls electrical energy , which can determine the energy efficiency of the entire vehicle; to understand it simply, it is the "CPU" in the power electronics industry.
Generally speaking, IGBT accounts for about half of the cost of the motor drive system, and the motor drive system accounts for 15-20% of the total vehicle cost, that is, IGBT accounts for 7-10% of the total vehicle cost, which is the cost other than the battery * Expensive parts.
Not only do motors use IGBTs, new energy generators and air conditioners also require IGBTs. Not only are new energy vehicles, the core of DC charging piles and locomotives (high-speed rail) is also IGBT tubes. 30% of the raw material cost of DC charging piles is IGBT.
China IGBT Development
What is such an important high technology in China?
As you would expect, for a long time, the core technology of IGBT has been in the hands of Europe, America, Japan and South Korea. In order to achieve technological breakthroughs, IGBT is the second most important national technology breakthrough during the 12th Five-Year Plan period.
In 2008, CRRC Times Electric Co., Ltd. acquired a 75% stake in UK-based Dennis Semiconductor, the world's earliest IGBT technology developer.
In September 2009, BYD IGBT chips passed the scientific and technological achievements appraisal organized by the Power Electronics Branch of the China Electrical Equipment Association.
In 2014, CRRC Zhuzhou produced 8-inch IGBT chips with full intellectual property rights. Since then, China's high-speed rail and new energy vehicles have begun to have a "Chinese heart."
In 2015, CRRC IGBT converters were exported overseas for the first time, and orders for 100 locomotives in India were obtained.
1000只订单。 In March 2018, CRRC Times Electric's IGBT modules defeated international competitors and won 1,000 orders from India again.
市场有了小批量订单。 In addition to India, CRRC's independent IGBT chips are still in Malaysia; there are small orders in Russia, Italy and Central European markets.
On December 10, 2018, BYD released IGBT4.0 technology. According to reports, this product has greater output power, smaller comprehensive damage, higher reliability, and longer service life.
Chinese and foreign IGBT gap
It is precisely because of CRRC, BYD and many companies' persistent research and development that key IGBT components in China have been conquered, and their market share is constantly increasing. According to Academician Ouyang Minggao: By 2018, about 40% of IGBTs will Chinese enterprises.
But in fact, our gap is quite obvious. The development of China's IGBT is bound to be full of thorns.
According to a report published by an international research organization in 2016, Infineon Germany ranked first with a global share of 24.5%, Japan's Mitsubishi Electric ranked second in the world with a 24.4% share, and FujiElectric captured 12.2% Third place.
In addition, Hitachi, Toshiba in Japan, Fairchild in the United States, SEMIKRON (Simon Kang) and ABB in Europe all rank high in the world. CRRC ranks about tenth.
So, what is the gap between our IGBT and foreign advanced IGBT?
First of all, from the aspects of technology, craftsmanship, efficiency, and materials, we still have obvious shortcomings. For example, BYD has its own IGBT. BYD economy vehicles use its own IGBT, but excellent models will use imported products because imported products will have a lower power consumption.
Specifically, there are two key points of IGBT technology, one is heat dissipation, and the other is backplane technology. Among them, the key material science is the weakness of China and the superiority of Japan.
Next-generation SiC (Silicon Carbide) for IGBT
Japan's superior technology is silicon carbide.
Toyota has publicly stated that SiC has the same importance as gasoline engines. Since the 1980s, Toyota has been researching SiC, 30 years earlier than its international counterparts.
What makes Toyota attach so much importance to silicon carbide? After all, the current cost of SiC materials is estimated to be 8-10 times that of IGBT.
Because silicon carbide is a more advanced power electronic chip used as a controller, the specific power of the motor can be increased by greatly increasing the speed of the motor. Its frequency and efficiency can be very high, and its volume can be very small. The reduction of IGBT should be about 70-80%.
With reference to the US Department of Energy's 2025 target, the power density of the motor is 50 kW / L, and the silicon carbide controller is 100 kW / L.
Silicon carbide also has the advantage of low loss at high frequencies, which can improve the efficiency of the vehicle by about 10%, which also means that the mileage can be improved, and the battery cost may be significantly reduced.
In terms of application, the controller used by Tesla Model 3 is silicon carbide, and BYD also announced that it has invested heavily in the layout of the third-generation semiconductor material SiC. In addition, many domestic teams have begun industrialization.
。 Academician Yang Minggao estimates that silicon carbide will replace IGBT by 2025 . With this timetable, China will keep pace with the world.