Reading experience of "Lane-Changing Racing: China's Road to New Energy Vehicles" - 1

beyond_笑谈

Reading experience of "Lane-Changing Racing: China's Road to New Energy Vehicles" - 1 [Copy link]

After receiving the book "Lane Changing Racing: China's Road to New Energy Vehicles", I couldn't wait to read the first few chapters in the past few days. The book systematically explains the birth and development of automobiles, especially with the development of electronic industry technology and people's higher-level definition of traditional automobile functions, which invisibly highlights the inevitability of the automobile industry gradually developing towards energy saving and intelligence.

After reading the article, I have the following rough insights mixed with some personal opinions.

1. The birth of the automobile and the development trend of modern motorization.
   1. With the industrial revolution, it provided technical support for the machinery, power drive and electrification of the automotive industry.
   2. With the development of integrated circuits and electronic industry technology, the various ECU designs (electronic control units) of automobiles will inevitably be integrated, so that modern automobiles tend to be more integrated and smarter.
   3. In recent years, the development of Internet of Things technology has also been reflected in the automotive industry. In the early years, the company has been developing Internet of Vehicles technology, which also caters to the needs of market applications.
   4. With the air pollution caused by traditional fuel vehicles and the awareness of the global energy crisis, the development of new energy vehicles has become a necessary option.
2. my country's outlook, layout and industrial development of new energy vehicle industry
   1. Coinciding with the time when the automobile industry is transforming from fuel to electrification, my country has seized the opportunity to change lanes and conduct early research on new energy vehicle technology and realize the productization of new energy vehicles.
   2. With the help of the Beijing Olympics, not only the performance of new energy vehicles was verified, but also my country's technological strength in the industrialization development of new energy vehicles was successfully demonstrated to the world.
   3. Remove restrictions on the share of foreign investment in new energy vehicles and allow the new energy vehicle industry to adapt to market competition and achieve healthy development.
3. The topics that cannot be avoided in the development of the new energy vehicle industry: charging and battery replacement
   1. When the investment and returns were initially disproportionate, the government took the lead and state-owned enterprises took the lead in building charging piles to break the bottleneck of new energy vehicle charging piles.
   2. According to the market application environment, we advocate the construction of charging piles according to local conditions to lay out the healthy development of the new energy vehicle industry.
   3. After the charging conditions are met, the next step is to improve the charging performance: fast charging, and to improve the charging experience: battery swapping. When the battery swapping piles for new energy vehicles are fully covered, the application of new energy vehicles will be greatly popularized.
4. Core components of new energy vehicles: three-electric system
   1. With the development and popularization of new energy vehicles, the internal combustion engine power system components of traditional fuel vehicles: engine and gearbox are gradually being replaced by the core three-electric system of new energy vehicles: battery, motor and electronic control.
   2. As a key component of new energy vehicles, power batteries are also being upgraded with the development of technology. When I was making power tools ten years ago, power batteries mainly used 18650 cylindrical lithium batteries. But now new energy vehicles have introduced 4680 square batteries with larger volume and power density.
   3. Due to the high power density of lithium batteries and the high bus voltage of new energy vehicle battery packs (200V ~ 750V, and 800V technology is currently in use), the battery management system is particularly important. Twelve years ago, I designed a battery pack charging and discharging test equipment for the company's sweeping robot battery pack. At that time, the battery pack used 12 nickel-metal hydride batteries in series, and the battery pack bus voltage was only 14.4V. The test equipment only needs to consider the pre-charge current, constant charge current and trickle charge current, discharge current, discharge voltage, battery pack temperature during charging and discharging, and the charging and discharging time range of battery packs of different capacities. Compared with the battery management system of new energy vehicles, it is also necessary to consider the safety protection of the battery pack during charging and discharging and the battery life considerations. For example, during fast charging, the temperature and charging current of each battery cell will affect safety. In order to increase the service life of the battery pack, it is necessary to collect the voltage of each battery cell and use active balancing (AFE) or passive balancing (DFE) technology to balance the power of each battery cell. The various parameters of the battery pack not only need to be collected and fault diagnosed, but also need to transmit data to the car's display interface and even the mobile phone terminal through the communication bus.
   4. As the driving component of new energy vehicles, the motor undertakes the work functions of traditional fuel vehicle engines. Permanent magnet synchronous motors are not only used in the field of industrial servo control, but also in the new energy vehicle industry due to their small size, light weight, power density and high efficiency. If the working temperature of the motor is too high, not only will the enameled wire of the motor be at risk of damage, but the motor will also be demagnetized, so heat dissipation during motor operation is very important.
   5. The importance of motor control systems (electronic control) for new energy vehicles is self-evident. Unlike the use of MOSFET as a driving power component in the field of low-voltage and low-power motor control, the motor controller of new energy vehicles mainly uses IGBT. However, the SiC MOSFET introduced in recent years is also being tried by some manufacturers due to its high withstand voltage and low on-resistance (high efficiency). To expand on this, in the field of industrial control, the main driving power components in high-power servo drives are also IGBTs or IGBT modules, and SiC MOSFETs are also being tried. With the gradual development of semiconductor technology, it is believed that the performance of motor drive power components (such as IGBT, SiC MOSFET) and the driver chips (gate drivers) of power components will also be improved, thereby improving the efficiency of the motor control system and improving the endurance of new energy vehicles.