Why is BYD's new hybrid technology on par with Toyota?

Recently, the news that BYD is about to launch the fifth-generation DM-i hybrid technology has attracted widespread attention. Today, we're going to take a closer look at the technology and how it's evolved.

In recent years, the domestic hybrid vehicle market of domestic domestic brands has shown a strong growth momentum, which has formed a strong challenge to the market share of hybrid models of joint venture brands. In this competition, BYD's DM-i super hybrid technology is particularly eye-catching.

BYD's R&D in the field of hybrid technology began in 2004, and in 2008, the company successfully launched the world's first mass-produced plug-in hybrid vehicle, the F3DM, which marked BYD's first breakthrough in the field of hybrid technology.

In the following ten years, BYD continued to conduct in-depth research and innovation on hybrid technology, accumulated rich experience and obtained many patents.

In 2020, BYD strategically subdivided the plug-in hybrid technology and launched the DM-i super hybrid technology with "ultra-low fuel consumption" as the selling point, which has been highly recognized by the market for its excellent fuel economy and power performance.

On January 11, 2021, BYD announced the official debut of DM-i super hybrid technology, and confirmed that the technology will be applied to three new models: Qin PLUS DM-i, Song PLUS DM-i, and Tang DM-i, and these models immediately launched pre-sales. This is not only a milestone in BYD's technological innovation, but also another proof of its continued leadership in the field of new energy vehicles.

Of course, we are not committed to tracing the comprehensive development process of BYD's DM-i hybrid system, but focusing on the in-depth analysis of BYD's fifth-generation DM-i hybrid technology.

Not long ago, BYD revealed at a recent internal communication meeting of the core management that it will launch the fifth-generation DM system, according to relevant participants, the fifth-generation DM-i has a fuel consumption of 2.9L per 100 kilometers, and it can run nearly 2000 kilometers with full fuel and full power.

The announcement of the news has undoubtedly triggered a wide and far-reaching impact, you know, most of the current hybrid models 100 kilometers of fuel consumption is basically controlled at the pace of 3-5L, and less than 3L is basically like the "Kármán line", very difficult to cross.

Although it is unconfirmed, there is even news that BYD has decisively denied this statement, so can the legendary fifth-generation DM-i be able to "work"?

Let's start with a suspected fifth-generation DM-i patent drawing from BYD.

When I first looked at this patent drawing, I was struck by the striking similarity between the technical effect shown and Toyota's THS.

That's right, it's Toyota's famous "sun gear" hybrid technology.

We can see that BYD's hybrid technology adopts a double planetary gear design, which is different from the previous fourth-generation DM-i technology scheme.

The system combines dual electric motors and conventional differentials, and offers front-wheel drive and rear-wheel drive hybrid modes, with four operating modes: pure electric four-wheel drive, hybrid four-wheel drive, extended range rear-wheel drive, and high-speed engine direct drive.

So, is BYD's design infringing?

We know that Toyota's THS hybrid technology emerged in the early stages of hybrid technology, and its planetary dual-motor hybrid system architecture makes it unique in the hybrid field. With excellent fuel economy and consistent and reliable quality, THS hybrid technology has won wide acclaim in the global automotive market.

In fact, Toyota's THS hybrid system is not independently developed, but is based on the planetary hybrid technology of the American company TBW.

TBW filed a patent in 1969 for the purpose of serving General Motors, and the patent expired on March 2, 1988. Toyota registered a patent for the THS planetary dual-motor hybrid system on May 20, 1996, and officially put it into mass production on the first-generation Prius model in 1997, ensuring the legitimacy of its technology. Since then, this technology has been widely used in Toyota's HEV diesel-electric hybrid models such as Corolla/Leiling Shuangqing, Camry HEV, RAV4 Rongfang HEV, Highlander HEV, Sena SI∈ NNA, etc., and has won wide recognition in the market.

Later, Toyota gradually released its THS patents in China, and in early 2019, it transferred THS technology to its core component supplier Corun in China at a symbolic price of "US$1". It is worth noting that Geely Automobile holds a majority stake in Corun Automobile, so to some extent, Toyota actually indirectly transferred THS technology to Geely Automobile.

It should be pointed out that although Toyota has obtained the patented technology of THS, it has carried out a lot of improvement and upgrading work on the basis of the original technology. It is these efforts and innovations that have enabled Toyota to achieve what it is today.

Let's continue to talk about dragging back to BYD's fifth-generation DM-i, so what is the difference between it and Toyota's THS hybrid technology?

According to the patent drawing, the system uses one engine with two motors to achieve power transmission through two sets of well-designed planetary gears, cleverly omitting the traditional clutch, thereby improving the overall connection strength and efficiency.

Exploring the underlying reasons for BYD's switch to planetary gear technology, one might wonder why it abandoned hybrid technology, which had performed well.

BYD's old EHS hybrid system abandons the traditional gearbox, and in most cases is mainly driven by an electric motor, and the engine acts as a generator, only directly driving or parallel driving the vehicle at high speed or rapid acceleration.

Although this design simplifies the structure and reduces the cost, it is not possible to generate power at the same time during high-speed direct drive, which can lead to a drop in battery power during frequent acceleration, causing a rare stall occurrence

However, with the introduction of planetary gear technology, the power of the engine was efficiently distributed, which cleverly solved this problem.

In addition, the use of the double planetary gear structure not only eliminates the clutch and reduces the volume, but also improves the efficiency of the system by distributing the power of the planetary rows, and the working pressure of the engine and motor is shared by the two planetary rows. The engine's direct-drive capability has been enhanced, resulting in a wider range of efficient operating conditions. At the same time, the motor can also be changed in two gears through the planetary row, so that the motor with less power can be used and the cost can be reduced.

Despite the multiple challenges of this design, such as the increased complexity of the structure and the difficulty of planetary gear machining, domestic component suppliers have also encountered bottlenecks in terms of product durability. However, I firmly believe that BYD must have thought carefully in this regard, and may have made a breakthrough at the technical level and successfully achieved mass production.

In addition to the new hybrid technology, the research and development of another BYD technology is also on the hot search, and it is also the key to the fifth-generation DM-i hybrid system.

This is BYD's second-generation blade battery.

Blade batteries are no stranger to you, with the advantage of their compact structure and efficient energy storage capacity. Compared with traditional cylindrical or prismatic batteries, blade batteries have a higher volume utilization rate and are able to provide more energy in a limited space. At the same time, its flat shape also makes it easier to integrate into a variety of devices, giving designers greater flexibility.

In addition to the structural advantages, the blade battery also performs well in terms of safety. Due to the use of safety measures such as multi-layer structure and thermal isolation, the blade battery can quickly cut off the heat source and prevent the occurrence of thermal runaway in the event of short circuit, overcharge and other abnormal conditions. This self-protection mechanism greatly reduces the risk of battery fire or explosion, providing users with a safer power environment.

And the second-generation blade battery can be described as the "PLUS" version of the first generation.

According to the collected information, the advantage of the second-generation blade battery is its significantly improved volume utilization, which is more than 40% larger, allowing more battery cells to be accommodated in the same space, which directly leads to an increase in the energy density of the battery pack, which in turn significantly increases the vehicle's range.

In terms of energy density, the energy density of the second-generation blade battery has reached 190Wh/kg, which enables the range of pure electric vehicles equipped with this battery technology to exceed 1,000 kilometers.

In addition, in order to meet the needs of different models and platforms, the second-generation blade battery has been carefully adjusted in terms of cell size. In addition, the optimization of the thermal management system, including the addition of liquid cold plates and thermal conductivity layers, not only improves the charging and discharging efficiency of the battery, but also prolongs the service life of the battery, ensuring stable performance under various working conditions.

Safety is another highlight of BYD's second-generation blade battery, its puncture resistance and anti-collision ability has been significantly enhanced, and the high-strength aluminum alloy plates added on the upper and lower sides of the battery cell form a solid honeycomb structure, which improves the compressive strength and rigidity of the battery, and provides a solid guarantee for the safe operation of electric vehicles.

Overall, BYD's fifth-generation DM-i hybrid technology achieves a significant improvement in superior power performance and fuel efficiency through its innovative dual-motor system and sophisticated planetary gear structure. In addition, thanks to the advancement of second-generation blade battery technology, the energy density and safety of the battery have been significantly enhanced, laying a solid foundation for the long-term development of electric vehicles.

Considering the range, if 2000 kilometers is used as the standard, when driving 40 kilometers per day, a full tank of fuel is enough to support nearly two months of driving, which undoubtedly highlights its excellent range and practicality. What do you think about the development of this technology that may herald the end of the era of combustion engine vehicles?