Text/Car Bright
Photo/Car Light
In the past one or two years, independent brands have made rapid progress in plug-in hybrid technology, and after BYD's DMi, Changan's iDD and Chery's Kunpeng e+ have also come out. Recently, I test-drove two models equipped with iDD hybrid and Kunpeng e+ hybrid, namely UNI-K iDD and Tiggo 8PLUS Kunpeng e+. Compared with BYD DMi-i, in addition to the increase in battery capacity, the main change is the addition of multiple gears. What is the point of so many gears? Is it to reduce fuel consumption?
New trends in domestic PHEV:
The battery is larger and the gears are more
BYD's DM-i, UNI-K's iDD, Kunpeng e+ is essentially very similar to Honda's iMMD structure, are all series and parallel mechanisms, the engine and motor can be mixed output, the motor can also be output separately, especially in the battery to the lowest power level that is, the feed state, can still make full use of the bottom residual power in the battery, to and fuel power for combined distribution, to ensure that even in the case of feeding, can also have the same low fuel consumption as the hybrid. However, unlike Honda iMMD, in order to meet the needs of the policy, the domestic hybrid will add a large battery, which can support tens to hundreds of kilometers of pure electric driving, in fact, this pure electric output is not very significant for daily use, the main meaning is to exempt taxes and green cards, and if necessary, auxiliary output power.
From the perspective of battery capacity and mileage, BYD's DMi low-end version starts with a pure electric mileage of more than 50 kilometers, and a little higher than 112 kilometers. It can also be seen from this that BYD launched DM-i earlier, so the 50-kilometer pure electric endurance version, the significance of pure electric endurance is extremely limited, and it is inevitable that there are some policy speculations. But later, for example, like the UNI-K iDD battery capacity is larger, reaching 30.74 degrees, can support 130 km of pure electric endurance. Kunpeng e+ is a 19.27 degree battery that can support 100 km of pure electric endurance. Therefore, from the perspective of endurance, the later iDD and Kunpeng e+ have begun to emphasize the endurance of pure electricity. This estimate is also related to the changes in the overall environment. At present, private and public charging piles are becoming more and more popular, charging is becoming easier and easier, and many people can no longer buy it like before and can only burn oil.
Compared with BYD's DM-i, Kunpeng e+ and iDD also have a significant difference that both have increased the gear. For example, Kunpeng e+ is known as 3DHT, and the so-called DHT is the meaning of hybrid gearbox.
The iDD is a 6-speed three-clutch electric drive transmission. How to understand this? In fact, in a set of 6-speed wet dual-clutch transmission, and integrated a set of clutch devices placed on the input shaft of the transmission, this clutch is used for the separation and coupling of power and fuel power, so there are a total of three clutch devices, to achieve power and fuel power through 6 gears for output.
In contrast, the BYD DM-i only has a single-stage deceleration, and there is only one gear in the direct drive state of the engine, and the gears are not as many as those two. However, if you compare the data, you will find that in fact, there is no obvious gap in the fuel consumption of the models equipped with the three technologies. The official comprehensive fuel consumption is about 5L.
What's going on? If fuel consumption cannot be reduced, what is the significance of the increase in gearing?
What are the benefits of increasing gearing?
Before the test drive UNI-K iDD and Kunpeng e+, I actually had this confusion. But after test driving two cars, I found that the significance of the increase in gear numbers is that it allows the engine to have more opportunities and earlier to participate in the drive under various working conditions, reducing the burden on the motor system, thus ensuring better power performance and system stability. In other words, the significance of the gear increase is not mainly for fuel consumption (just a goal to take into account), but for better and more stable performance.
For example, when I was driving on the 8PLUS Kunpeng e+, the car offered both EV and HEV working modes, and if I started with EV mode, but adjusted to SPORT while driving, the system would automatically jump from EV to HEV mode. That is to say, the system defaults to that you are going to start racing, so it automatically puts the engine on standby at any time.
Tiggo 8PLUS Kunpeng e+ Because there are three gears that allow the engine to intervene earlier, in HEV mode, even if the power is sufficient, the engine will occasionally participate in the work at low speeds, especially when you are accelerating sharply. It's just that Kunpeng e+ is still mainly electric at this time, and although the engine will turn, it is only an auxiliary role. At this time, if you look at the instrument, you will find that the main drop in heV mode is pure electric endurance, and although the fuel mileage is dropped, the number of drops is very small.
But UNI-K iDD behaves more extremely. Because it has 6 gears, the engine intervenes earlier and has a wider range (or conversely, because the engine intervenes earlier, it provides 6 gears at the time of design). It also offers HEV and EV modes (i-X custom modes are also available, which we won't go into.
Let's start with its EV mode. As mentioned earlier, the Kunpeng e+ engine will not turn when killed in EV mode, but we found that iDD in EV mode, the engine will also be output. Because I slammed a few feet on the throttle after setting it to EV mode during the test drive, I felt like I could clearly hear the roar of the engine. Then it was found that after running for nearly 2 kilometers, the average fuel consumption was 6.4L. The average electricity consumption is 22.9 degrees. So this proves that it mainly uses electricity in EV mode, but if you drive violently it will still make the engine participate in direct drive.
After adjusting it to HEV mode, the power of this UNI-K iDD is basically not dropped, and the whole process is mainly based on the output of the engine. At the time of departure, it was about 50 kilometers of pure electric endurance, driving more than 20 kilometers, and returning to nearly 50 kilometers. There is also an energy recovery link when there is electricity in the middle, so when the inside and outside are offset, it is found that the power has not changed at all.
Therefore, the advantages of multiple gears can be seen more clearly through the test drive of these two cars: the engine has the opportunity to participate more widely in the working conditions of high, medium and low loads, and the combination of fuel and electricity energy output is more reasonable. BYD's single-stage deceleration, the middle and low speed down to the power, the high-speed range to the engine, such a combination of the motor battery is particularly dependent. In particular, in winter, charge and discharge slow down, or when the power is insufficient, the engine needs to start frequently to generate electricity. The Kunpeng e+ and Changan iDD allow the engine to intervene earlier through the multi-gear setting, which can reduce the burden on the motor and increase the adaptability to various working conditions.
This seems theoretically more fuel-intensive, but does it really turn out to be the case?
When I tested the Tiggo 8PLUS Kunpeng e+, when I consumed pure electric endurance to only about 10 kilometers, I found that the system could not support EV mode. At this point I think it's already in a feed state. In this case, I drove in HEV mode, about ten kilometers, and when I reached the end, the average fuel consumption was 6L.
When testing the UNI-K iDD, the battery always retains a pure electrical endurance of about 50 kilometers. When we drive in HEV mode, the pure electric range is not only not lost, but also slowly increasing (because energy is recovered along the way). In the end we ran out of the average fuel consumption of 7-8 liters. Because the pure electric endurance does not drop the number throughout the whole process, so I can think of this result as feed fuel consumption.
The official fuel consumption of both cars is 5L, and in actual driving, one increases by 1L and the other increases by 2-3L, which I think is a normal level. I even think the fuel consumption of Kunpeng e+ is even lower than I thought. The fuel consumption of UNI-K iDD is slightly higher, in addition to its engine power more involved, and its body weight is also related. Because of its large battery capacity, the UNI-K iDD weighs 2,075 kilograms, which is almost three hundred kilograms heavier than the Tiggo 8PLUS Kunpeng e+. Combined with the weight of the two vehicles, in fact, the fuel consumption of iDD is really not high. This means that as long as the algorithm of the energy management system is reasonable, even if the engine is more involved, it will not bring a significant increase in fuel consumption.
You may say that if increasing the gear is to make the engine more involved in the working conditions, then what is the hard work of plugging in the mix? It is better to use fuel directly to power.
I think the significance is that in addition to being able to get a green card and support pure electric driving, the greater significance is to improve the stability of the entire system and the adaptability to various complex working conditions. Everyone knows that the three-electric system is actually very fragile, the low temperature in winter is not good, the state of no power is not good, if the load is too large the motor and battery may not be able to hold up, if in order to adapt to the high load with a high-power motor and battery, it will increase the body weight and manufacturing costs. Therefore, with a "more active" engine, from time to time behind the motor, but also in more critical moments to stand out, the stability and load resistance of the whole system will be better.
Therefore, why UNI-K iDD is known as "global intelligent oil-electric dual drive", focusing on the stability and durability of "full speed domain, full field domain, full temperature domain, full time domain". Behind this, I guess it should be the result of the engine's intervention in more working conditions. After all, compared with the motor, the engine is synonymous with stable and reliable leather and durable manufacturing.
Of course, the engine is more involved, and the direct result is definitely more fuel-intensive than not intervening, but the power brought by it is better and the stability is higher, and this advantage cannot be ignored.
In actual driving, whether it is UNI-K iDD or Tiggo 8PLUS Kunpeng e+, there are excellent front, middle and back acceleration capabilities, zero hundred results one is 7 seconds and one is 8.1 seconds, compared to Tang's 8.5 seconds are slightly advantageous. And the engine is actively involved throughout the whole process, the overall power performance in addition to faster than the fuel vehicle, the roar when speeding up, the sense of pressure of the body, etc., these feelings, are very close to the fuel vehicle.
BYD's three-electric level is in a relatively leading position in the industry, the protagonist position of the motor in the entire system is unshakable, and the engine is always an auxiliary role. So since it didn't want the engine to take on a more important role, it was naturally reluctant to spend effort to study increasing gear. After all, the more complex the structure, the higher the cost.
Like iDD, Kunpeng e+ to improve the "presence" of the engine by increasing the gear, thereby improving the adaptability and stability of the entire system to various working conditions, it is also a new idea. In this line of thinking, fuel consumption is not the only goal.
END