BYD's latest DM-i 5.0 plug-in hybrid system has a 2.9L feed fuel consumption under the WLTC standard.
Many people don't know that the power parameters of 5.0 have been lowered to a certain extent compared to 4.0, but this has not affected the performance of the entire system.
Under the condition of decreasing power parameters and increasing vehicle weight, how did BYD achieve 2.9L fuel consumption? Let's take a look at BYD's magical hybrid system.
First of all, let's take a look at the specific parameters of the two generations of powertrains:
In comparison, it is not difficult to find that the power of the motor and generator related to power has decreased to a certain extent compared with 4.0, but the acceleration time of the larger and heavier Qin L is almost the same as that of 100 kilometers, and its fuel consumption is 2.9L. Behind all this is the adoption of many innovative technologies and excellent management strategies in 5.0.
Extreme thermal efficiency
Some time ago, Geely and BYD started a discussion about who is the world's first engine thermal efficiency, in fact, both BYD and Geely have achieved more than 46% engine thermal efficiency, which has belonged to the first echelon in the world.
Extremely high thermal efficiency means more efficient energy conversion and improved fuel economy.
And its hybrid engine identity abandons the limitations of traditional engine design. The BYD 5.0 engine has the industry's highest compression ratio (from 15.5 to 16), which is a significant improvement for a highly mature internal combustion engine.
The new engine also applies seven core technologies, including high tumble air duct, high-energy ignition, intelligent EFI system, and intelligent split cooling, to create such an extreme engine combustion efficiency.
EHS electric drive system
BYD's EHS electric drive system is composed of P1 and P3 dual motors + dual electronic control + single-speed reducer + direct drive clutch. The dual motors can be connected in series and parallel, and the engine and the drive motor can be completely separated and fully combined through the clutch, and there are planetary gears added.
At first glance, you may think that this is not Toyota's hybrid system, but it is not.
Toyota's hybrid system, when the electric motor is used to drive, because there is no clutch, the motor needs to drive not only the wheels, but also the engine.
BYD's system can completely disconnect the motor and engine through the clutch, which can further improve the drive efficiency of the generator.
Through this system, coupled with BYD's self-developed AI energy consumption management algorithm, it can achieve a variety of working conditions including: P1 motor direct drive, P1+P3 motor parallel direct drive, P1+P3+ engine parallel drive, engine drive P1 power generation and then driven by P3, engine direct drive and other working conditions.
The vehicle selects the best drive form in real time according to the current road conditions to achieve the ultimate energy management. Compared with 4.0, the efficiency of electric drive mode has been improved from 87.6% to 92%, and the power density has increased from 65kW/L to 75kW/L.
Battery technology innovation
BYD's redesigned plug-in hybrid blade battery takes into account both energy density and power density. Its energy density is increased by 15.9%, the discharge rate is 16C, and the feedback rate is 5C, which is increased by 20.3%.
At the same time, BYD's new second-generation battery direct cooling technology and pulse self-heating technology ensure the stability of battery efficiency under extreme working conditions, and ensure its endurance and stability.
In addition, the common 12V lead-acid battery in ordinary cars was abandoned by BYD, becoming the only model in the world to use a 12V lithium iron phosphate small battery, reducing the weight to 2.2KG and the charging and discharging efficiency reached 94%.
On the whole, the decline in the power of DM-i 5.0 generators and motors is certainly not due to technological regression or cost savings, but because of the new technologies brought about by its strong technical strength and innovation, which greatly improves the efficiency of the whole system and brings more redundancy.
This further achieves lower fuel consumption, resulting in a brilliant result of 2.9L fuel consumption.