If you say now that "there are only two hybrid systems in the world", then one is a new generation of hybrid systems of its own brand, and the other... Still something else.
Previous: We learned about the basic principles of the "Two Fields" hybrid technology and the "Haval Lemon Hybrid DHT System" and talked about the differences. In this article, we will talk about what is the new generation of hybrid technology, and then compare the hybrid systems of the three companies from 6 practical dimensions.
■ What is a new generation of hybrid systems?
There are many definitions of the new generation of hybrid technology, but there are some commonalities, such as: hybrid special engines, a new generation of hybrid transmissions and full-speed and all-domain hybrid control logic.
Fuel-efficient hybrid engine
Ryota's engine technology, no mention
As one of the core power sources, the "hybrid special engine" is indispensable, and the "engine" technology of "Ryota" is very strong, whether it is Toyota's "VVT-i technology" (variable valve timing system) or Honda's "VTEC technology" (variable valve lift system) is recognized by the industry as an efficient engine technology.
Great Wall Motor's hybrid engine
However, independent brands, including Great Wall Motors, also have the accumulation of engine technology, such as the 1.5T "hybrid special engine" mounted on the "Haval Divine Beast", which also adopts the Atkinson cycle, with a compression ratio of 13:1, a maximum power of 113kW, the peak thermal efficiency and high efficiency area range is far better than the "engine" of the fuel platform, and the comprehensive fuel consumption is not vain "Two Fields" model, but the "hybrid special engine" is a basic operation, and the two points mentioned since then are important.
Efficient and precise hybrid transmission
The Haval Lemon Hybrid DHT System has more ingenuity than the parallel-arranged fixed-axis gear train and two-speed transmission mechanism mentioned above. For example, in solving the multi-gear hybrid system, there may be bumps and noises when changing gears.
The shift principle of the "Haval Lemon Hybrid DHT System" is to switch between 1st and 2nd gears through two sets of "gears" controlled by a "synchronizer", and the control of the position of the "synchronizer" is precisely the strength of Great Wall Motors engineers.
Schematic diagram of how synchronizers work
The column once introduced that Great Wall Motors has a hybrid system called "Pi4", the front axle uses a "P0 motor" for the "engine" start and stop, and the rear axle uses an electric drive rear axle that can be shifted in two speeds (i.e. "P4 motor + two-speed transmission mechanism"), and it is clear that the accumulation of experience in this area has been brought to the "Haval Lemon Hybrid DHT System".
More agile dynamic response, smoother shift experience
The "Haval Lemon Hybrid DHT System" plays the role of the "motor" in shifting gears: since the "drive motor" can drive the vehicle alone and continuously, when the system needs to shift gears, the "drive motor" can temporarily take over the power output, wait for the "synchronizer" to complete the speed adjustment, and then return the dominance to the "engine", so that the entire switching process will not let people feel a trace of power interruption.
Schematic diagram of the main components of the Haval Lemon Hybrid DHT system
Of course, the "Haval Lemon Hybrid DHT System" also adopts a highly integrated structured design, integrating the "DCDC System" and "Motor Controller" in the entire power module to reduce the volume of the powertrain, reduce the weight, improve the transmission efficiency, improve the NVH control and other effects, which are the basic features of the new generation of hybrid systems.
Hybrid control logic at full speed and all domains
Another feature of the new generation of hybrid transmissions is that all working modes will be reasonably corresponding to different speed domains and different power requirements, which is what we often call "full speed full domain". Take the "Haval Mythical Beast" model, for example.
Different modes correspond to different operating conditions and road conditions
In the urban commuting, the speed is relatively low, generally below 35km / h, the system will drive the task mainly to the "drive motor", intelligently switch in pure electric mode and series mode, "engine" is mainly used for power generation after opening, and always maintain the highest efficiency of the working range; in the urban road is relatively smooth, need to quickly increase the speed, the "engine" will be driven by 1 gear set intervention; and when we want to overtake the rapid acceleration, the system switches to parallel mode, oil and electricity joint drive, Provides strong power; when driving on high-speed roads, the system cuts to the "engine" direct drive 2nd gear for direct drive.
The two-speed shift increases the overall efficiency of the powertrain
It can be seen that the "Haval Lemon Hybrid DHT System" understands the hybrid control more in line with China's national conditions, especially in response to various road conditions in the urban commute, the two-speed shift mechanism exerts its advantage of "fish and bear paw", while maintaining the "engine" in the efficient working range, it will not be limited by the power of the "drive motor", avoiding the shortcomings of not being able to speed up quickly.
■ Comparison of six practical dimensions
Then we compare the three hybrid systems from the six dimensions of fuel economy, dynamic performance, driving smoothness, NVH performance, power retention ability and feed condition comprehensive performance.
Fuel economy
First of all, the "Toyota THS Hybrid System" realizes power shunting through the "planetary gear mechanism", calculates the optimal speed of the "engine" in real time using the vehicle driving conditions, the status of the power battery, the throttle brake signal, etc., and cooperates with the "Atkinson engine" with a thermal efficiency of more than 40% to achieve efficient driving of the "engine" under full working conditions. Therefore, in terms of optimizing the "engine" working conditions, Toyota's hybrid system is definitely the industry leader.
Into also planetary gears, difficult also planetary gears
However, in terms of the efficiency of the whole hybrid system, the situation has changed, because the "engine" and "motor" can not be separated, in the pure electric driving process, the "planetary gear mechanism" will rotate accordingly, resulting in a certain power loss. In order to meet the high power demand, the "engine" must increase the speed, get out of the optimal working range, and finally reduce the fuel economy of the system. It's like three people participating in a tug-of-war, but two of them don't have a good relationship, one person has to mediate, and finally two people contribute, one person does the cheerleading.
Honda i-MMD hybrid system in addition to the ENINE mode, the rest of the working conditions are basically left to the motor to drive
Then look at the "Honda i-MMD hybrid system" its core logic is also the "engine" always works in the efficient area, but the way of implementation is different from Toyota, when the power is insufficient, the "motor" output energy to supplement the power; when the power is abundant, the excess energy will be stored in the battery to achieve the purpose of fuel saving. However, due to the lack of two-speed regulation, the direct drive of the engine is limited.
The new generation of hybrid systems provides better control of fuel consumption
The "Haval Lemon Hybrid DHT System" inherits the fuel-saving attribute of the "Honda i-MMD Hybrid System", and the two-speed regulation allows the "engine" to intervene in the power output at low and medium speeds, further expanding the role of the "engine" in the efficient range. In addition, compared with Toyota's "planetary gear" structure, the parallel shaft structure has higher transmission efficiency, up to greater than 97%, and is more fuel-efficient. In the urban area, the fuel consumption than the traditional fuel model fuel saving rate of up to 35 ~ 50%, in the high-speed working conditions, the engine direct drive mode of fuel consumption, than a single tandem mode hybrid system can reduce the fuel consumption of 10 ~ 15%, it can be said that the higher the speed, the more significant the fuel saving. Therefore, the "Haval Beast DHT" WLTC has a comprehensive fuel consumption of 5.5L/100km.
Power performance
In fact, it is not reasonable to talk about power performance with Toyota's hybrid system, and the purpose of the "E-CVT" is to save fuel, not to be powerful. Therefore, as a fourth-generation "Prius" owner who has been driving for 1 year, the fuel economy is the focus when buying a car. After a period of time, the "Lexus CT200h" was opened, and the biggest feeling when I opened it was the "Buddha", which can be described as the "chou) and the benefit (wei) benefit (xiang) zhang (tou) of my "Buddha".
The biggest feature of the "Honda i-MMD Hybrid System" is that the power performance is strongly bound to the power of the "drive motor", and the power of the "drive motor" is related to the strength and axial space of the "hollow shaft". Therefore, when the power demand exceeds the rated power of the "drive motor", the power performance will drop significantly, and I believe that friends who have driven the "Honda i-MMD hybrid system" should have a feeling of slower acceleration after the middle and high speeds.
The DHT100+1.5L combination used on haval models
In contrast, the two-speed transmission mechanism of the "Haval Lemon Hybrid DHT System" allows the "engine" to quickly intervene in the drive, ensuring the power performance under the full speed range, and the low-speed medium speed plays the advantages of pure electric drive static, fast and smooth, and the role of the "engine" begins to be played at medium and high speeds, and the "economic direct drive" (that is, the series mode) and the "power direct drive mode" (that is, the parallel mode) are switched to ensure the agility and strength of the speed increase. The haval mythical beast model has an acceleration time of only 4.3 seconds from 0 to 60 km/h, which can be said to be a hybrid system that crushes the "two fields".
Driving smoothness
The "planetary gear mechanism" of the "Toyota THS Hybrid System" achieves the effect of stepless speed change, so it is also known as "E-CVT", acceleration must be "silky feeling" linearity, and "Honda i-MMD Hybrid System" does not have a shift mechanism, just consider the adjustment of the "clutch" opening and closing, obviously, everyone can still believe in Honda's skills, as long as it is not a fierce driving, basically will not feel the "engine" involved in the moment.
DHT is more efficient and responsive
Although the "Haval Lemon Hybrid DHT System" has added a two-speed transmission mechanism, the Great Wall engineers cleverly used the "motor" and "synchronizer" coordinated shift technology to minimize the possibility of intervals and setbacks in the whole process, so we also don't have to worry about the smoothness problem.
NVH performance
In principle, the Toyota THS Hybrid System is the best set of three systems to control NVH, because the three power sources are not decoupled. However, in the actual driving process, for some car owners who like to drive fast cars and step on "floor oil", they must accept the experience of "engine light roar does not speed up". The "Honda i-MMD Hybrid System" will have a rapid drop in power after a long period of high power output, and the "battery" needs to be quickly replenished, at this time, the "engine" as a "range extender" needs to operate at full capacity, and it may deviate from the optimal working area, resulting in "engine" noise.
A motor with a stator low harmonic winding structure
The "Haval Lemon Hybrid DHT System" can be connected to the drive earlier due to the two-speed speed regulation, which theoretically reduces the situation that the "drive motor" relies on the "battery" for a long time to produce a large power output, and effectively suppresses the noise from the "engine". In addition, similar to Honda's hybrid calibration logic, the urban road condition "drive motor" is still the main driving source, so Great Wall Motor's engineers optimized and upgraded the "motor", using the "stator low harmonic winding structure" and "rotor three-stage oblique pole type" to reduce the "whistle" when the high-speed "motor" runs. At the same time, the entire hybrid transmission also adopts a high gear coincidence design, which further improves the NVH performance.
Power retention (feed-in) capability
Although the "Toyota THS Hybrid System" uses the lever principle of the "planetary gear mechanism" to achieve a series mode by fixing 1 to 2 components of the three rotating mechanisms (that is, the "MG1 motor" generates electricity and the "MG2 motor" is responsible for driving), unfortunately, the system cannot maintain the series mode for a long time, and the feeding capacity is limited. In addition, due to the structure and volume, it is difficult to configure a high-power "MG1 motor" for power generation, so the power retention ability is poor. However, you don't have to worry about Toyota's HEV model losing power, because the "Toyota THS Hybrid System" was originally designed not for electric drives, but to make the "engine" more fuel-efficient. After entering the PHEV era, the second-generation "Toyota THS Hybrid System" has been adjusted and the calibration of electronic control has been carried out, and we will talk about it when we have time.
Haval Lemon Hybrid DHT system in series mode
The "Honda i-MMD Hybrid System" and the "Haval Lemon Hybrid DHT System" both have separate series modes, but the "Haval Lemon Hybrid DHT System" has expanded the scope of use of the tandem mode after adding a two-speed transmission mechanism, that is, using the 2nd gear of the transmission, maintaining the series mode at medium and high speed, so that the "engine" continues to power up the battery, so the power retention performance is better.
Comprehensive performance of feeder conditions
In addition to some of the reasons mentioned above that the "Toyota THS Hybrid System" is difficult to keep power, because the "motor" cannot be decoupled from the "engine", the "engine" will drive the inertial rotation of the "motor", which will increase the loss of energy, and further aggravate the problem of the "engine" inefficiency at low and medium speeds, making the fuel economy worse. However, again, the core is the "engine", which can use less electricity and reduce the need for feeding.
Schematic diagram of the structure comparison between the Honda i-MMD hybrid system and the Haval Lemon hybrid DHT system
The "Honda i-MMD Hybrid System" and the "Haval Lemon Hybrid DHT System" have advantages over the "Toyota THS Hybrid System" in terms of fuel economy and power in terms of feed-in electric conditions. The "Haval Lemon Hybrid DHT System" has greater advantages, because its "range extender system" and "drive motor" are arranged on two separate "input axes", theoretically the "range extender system" has less interference with the "drive motor", so it will perform better in NVH.
■ Summary
Full layout of the lemon hybrid DHT system
In 2020, Great Wall Motors, as the first independent brand in China to release a new generation of hybrid system, has rolled out its hybrid layout, and we can see from the table that the entire "lemon hybrid DHT system" can cover A~C class models, and there are more and more Haval models equipped with the system.
Equipped with the Haval Lemon Hybrid DHT system Haval Mythical Beast
Haval family as a long-term domination of the domestic SUV market model, now matched with the "Haval lemon hybrid DHT system", can be described as a tiger to add wings, so that the pursuit of cost-effective consumers have been a fuel-saving consumption upgrade, with the listing of "Haval God Beast", I believe that the Haval family will lead the SUV into a new era of hybrid.
■ The world has changed
Finally, I would like to thank all the self-brand engineers who continue to fight for hybrid technology, because of you, the world has changed.
If you say now that "there are only two hybrid systems in the world", then one is a new generation of hybrid systems of its own brand, and the other... Still something else.