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With the rise of this wave of DHT hybrids of independent brands, the hybrid field that has been suspended for many years has become "a pot of porridge in the northwest of Jinxi".
DHT broadly refers to "electrified transmission dedicated to hybridization", which is different from the "traditional multi-gear AT/DCT transmission + P2 single motor" hybrid that has been widely used until now. It is precisely because of the core feature of "dedicated", their basic structure and principle, and any kind of mechanical transmission that we are familiar with are completely different.
So before you understand the DHT hybrids of each family (see "Just for Better Mixing, DHT Universe Kills Crazy"), it is actually necessary to review some of the basic terms of hybrids, as well as update the new era understanding of these "old friends".
Not in Ali, also look at the P number
Three sentences are not far from the P number, in addition to Ali and car companies. But when it comes to hybridization, it is difficult to avoid the motor prefixes of P0 to P4. The P here refers to the position, which is where the motor is located in the entire drive train (power train/PT).
Hybrid hybrid, since it is mixed, it must be added to the motor. Where this is added, it will determine the "can or can't" of the motor, which also determines the principle and performance of the hybrid system. With some exceptions, the motor can have five positions of P0, P1, P2, P3 and P4, and the hybrid system can choose one of them to arrange the motor, or it can form multiple motors/generators in multiple positions.
P0 refers to the other end of the engine's power output shaft, i.e. the front end of the longitudinal engine, or the opposite side of the transmission of the transverse engine. A class of 48V light mixing systems, BSG motors, belong to the P0 position motors. Among them, B refers to the belt, because one side of the engine output power needs to be connected to the transmission shaft, so the other side is connected to the belt drive of the air conditioning compressor and other accessories, BSG motor usually replaces the original starting motor located in this position.
Because the entire engine is separated from the power output shaft, the P0 motor can only be used for power generation or auxiliary start, as well as a certain degree of kinetic energy recovery, but it cannot have a greater impact on normal driving. Therefore, the same as the 48V light mix, if the ISG motor (P1) is used, it can usually be approximated for a short time to pure electric travel (extending the taxiing distance); and the 48V light mix using the BSG motor (P0) cannot do this.
In general, with highly electrified hybrid technologies like DHT, P0 motors are basically negligible (DHTs rarely require P0).
Position of the BSG motor
P1, P2, P3 motors are located in the three intermediate positions of "engine (output shaft/transmission shaft) - clutch (including hydraulic torque converter, etc.) - transmission (gear) - drive shaft / wheel (reducer, differential)". The spacing of these things makes the motors in these positions have functional differences.
The P1 motor cannot be separated from the engine before the clutch, and its rotation cannot be decoupled from the engine. In layman's terms, as long as the engine is running, the motor will inevitably rotate, you turn me, I turn you have to turn. Therefore, the P1 motor cannot work alone, that is, the hybrid system with only the P1 motor cannot achieve pure electric drive (the 48V ISG motor mentioned earlier only "approximately" pure electric driving when coasting).
But on the other hand, also because before the clutch, the P1 motor was well suited as or as a generator. Especially in the hybrid system of multiple motors/dual motors, regardless of whether the clutch is disconnected or not, no matter what the working state of the motor and gear downstream of the drive train, the engine is always driving the P1 motor, as long as it is needed, it can generate electricity.
This is the i-MMD, and the range-extended mode requires a motor/generator at both ends after the clutch is disconnected
This is actually the series mode in the extended range hybrid and DHT hybrid, to achieve such a "fuel generation - motor drive", it is necessary to disconnect the clutch, there are motors /generators on both sides of the clutch: the fuel side has a generator to generate electricity, the middle clutch is disconnected, and there is a motor drive at one end of the wheel.
So in the new DHT hybrid systems that emerge today, the P1 position motor is often indispensable.
Note the relative position of the clutch, Kunpeng DHT is the motor in the frame equivalent to the P1 position when the leftmost clutch is closed
The P2 motor is located between the clutch and the transmission and is sometimes contained in the transmission housing, forming the so-called "HAT/Hybrid AT". For a long time, traditional brands launched hybrid models (especially plug-in hybrids) in this way, sometimes with P3 or P4 motors.
Because after the clutch, simply disconnect the clutch and the P2 motor can be driven separately to achieve pure electric mode. Because it is in front of the various gears of the transmission, even when driving purely electric, multiple gears can be used to take into account different speed conditions. Therefore, the motor does not need to be very powerful, which can reduce the volume and cost. However, because the motor power must eventually pass through the gear and then to the wheel, even if it is purely electric, it must face and solve the impact of gear shifting on the smoothness.
Lynk & Co 01 HEV and Kunpeng DHT because they use dual-clutch transmissions, with two clutches and two power shafts, the position motor is placed on one of the power shafts, so it is called P2.5 motor. Essentially this is also a special branch of the P2 motor.
Note that Kunpeng's left motor is not P1 in the standard sense: there is also a clutch upstream of it
The P3 motor, behind the entire transmission, near one end of the wheel, is clearly capable of supporting pure electric drive. Because it operates downstream of the transmission, it can no longer use the transmission gear to regulate its own operation, and achieving a separate drive vehicle (pure electric or range extended mode) requires more power, which means a larger volume and higher cost.
But also because of the departure of the transmission, the P3 motor can completely avoid the impact of switching gears, and can also help reduce the impact of shifting on the side of the internal combustion engine by adjusting its own speed and torque in hybrid mode.
As for the P4, it has little to do with "mixing" in essence, it is located on another axle of the non-internal combustion engine drive shaft. If the vehicle itself is not a mechanical four-wheel drive, the P4 motor and the engine are completely without mechanical connection, and there is no "how to mix" problem.
The P4 motor can be understood as the "second engine" on another axle, which is nothing more than a motor and not a fuel engine, which can be said to be a veritable "double engine". Most P4 motors exist only to achieve four-wheel drive and supplemental power, and it can be added to almost any hybrid system. The E-Four electronic four-wheel drive model in the Toyota hybrid and the Mocha DHT-PHEV that Weipai emphasizes power are all P4 motors added to the original hybrid.
Toyota E-Four, note that the rear axle is only connected by orange cables in the direction of the front of the car
In addition, the PS in the figure below refers to a motor with a PowerSplit power shunt device (usually a planetary gear set structure). In fact, most of these hybrid systems completely abandon the traditional mechanical gear (not even single gear), so the naming method of the P-table is actually partly (mainly the P1 to P2 part) because of the fuzzification lost value.
For hybrid systems that apply planetary gear sets, such as Toyota THS, Geely Thor Hi· X DHT Pro, universal Volttec, etc., the position of the motor needs to be analyzed on a case-by-case basis. In particular, the latter two also have a variety of power transmission paths controlled by the clutch, and the motor in different working modes is also changing in the "P number".
The historical problem of plugging in or not
"There are only two kinds of hybrids, two fields and the other", which has always been said in the folk. From a pragmatic point of view, this statement does make sense and value. THS and i-MMD are the two representatives of the DHT hybrid that have risen successively – although they did not have the term "DHT" when they appeared.
However, if you look deeper, there are actually some other "coincidence factors" behind it: for example, GM and Ford also hope for planetary gear PS hybrid, but they have not achieved market success; for example, other mainstream joint ventures and even independent brands do not enter the mainstream in pursuit of hybrid, but use plug-in hybrid to obtain environmental protection regulations, and naturally will not bother to study DHT hybrid.
This has also formed the basic pattern of hybridization in the past: either the DHT non-plug-in hybrid of the two fields, which is fuel-saving but does not have a green card and lacks policies; or the non-DHT plug-in hybrid of other brands, with green cards and policies but poor experience. So there is a conclusion that "two fields are good, non-plug mixing is good, other brands are not good, plugs and mixing are not good".
HeV and PHEV, the essential difference is only where the electricity comes from
In fact, the difference between a hybrid HEV and a plug-in hybrid PHEV only limits "whether (can) be plugged in". The poor "P" is "Plug-in", whether it can be inserted into the charging gun and connected to the grid for charging. As for which "mixed" way to use, there is no limit at all.
It is the subjective choice of the real environment and car companies, which just formed the past pattern of "HEV is mostly DHT hybrid, PHEV is mostly non-DHT hybrid", rather than what are inherently good and bad characteristics of the two.
Recently, consumers have slowly clarified this once cognitive limitation. The same is "two fields hybrid", the plug-in version of THS and i-MMD has been hanging a green card on the road in the past two years; the same is "non-plug-and-mix", there have also been some brands based on the non-DHT P2 architecture to create HEV, but the sales are not much and the popularity is not high.
Today, the DHT hybrid launched by independent brands further illustrates this point. The first is fuel consumption and performance performance, these new DHT hybrids can catch up with or even surpass the performance of "two-field hybrid" (of course, it is also necessary to take into account that the latter has appeared for many years); secondly, even if it is inserted, the two-field and independent brand DHT plug-and-mix version have also achieved far more than the comprehensive performance of non-DHT hybrid/plug-in hybrid.
Therefore, the saying that "hybrid only divides into two fields and the other" has expired, and it is better to update it to "hybrid only divides DHT and non-DHT". For today's hybrid models, the first thing to pay attention to is whether its hybrid structure belongs to DHT. As for whether it is plugged or not, many times it is only for consumer groups with different needs for license indicators, charging conditions, and pure electricity.
skewer? combine? mix?
If the curiosity is a little higher, whether the hybrid is "string/merge/mixed", it will inevitably enter the scope of your brain search.
Simple concatenation is the simplest. The so-called series connection is naturally on the same "line" as the engine and the motor. Engine power is completely output to the electric motor, which in turn is fully transmitted to the wheels – this is the standard range extender hybrid. Ideal ONE, Nissan e-POWER, lantu FREE are all familiar models, needless to say.
Nissan e-POWER extended range hybrid, the power only takes a line in series
Simple paralleling is not difficult to explain.
The so-called parallel connection, that is, the engine and the electric motor can work separately, of course, can also cooperate with each other. As long as this is met, it belongs to parallel, so P2, P3, P4 motors are all in parallel. Although they appear to be "stringed" together with the engine on the topology map, it is only because of the ring structure of the motor, which is equivalent to "sleeve" on the engine output shaft, and can essentially work in parallel with each other.
Single motor parallel hybrid, note that the red drive shaft is through the blue motor, the essence is parallel
As for the mixed connection, the vast majority of hybrids that cannot be attributed to the above two kinds of hybrids belong to the mixed links. As the name suggests, mixed connections can be paralleled, connected, or connected in series. Today's DHT hybrid mostly uses dual motors or multiple motors, the most typical P1 + P3 architecture, P1 is connected in series because it is rotated with the engine at any time, and P3 is a parallel connection that can work alone and can be mixed and stacked.
In addition, in complex hybrid systems, multiple clutches can control and change the path of power transmission, allowing a motor in the same hybrid system to switch between parallel or series roles in different modes.
For example, in Kunpeng DHT, when clutch 1 is closed, 2 is open, and 3 is closed, the upper motor is connected to the 2-stop power of the internal combustion engine through 1 or 3 gears alone; and when the clutch 1 is closed, 2 and 3 is open, or this motor, it becomes a drive motor in the series increase range.
So in "Just to Mix Better, DHT Universe Kills Crazy", I said there was no need to explain Kunpeng's block... It's too complicated
In today's context of the complexity of hybrid systems, string parallel mixing is almost every common choice. Pure tandem only appears on range extended hybrid models, and simple parallel connection has basically withdrawn from the historical stage, and only a few hybrid models that pursue extreme performance will continue to be used.
String-and-mixed will become the mainstream, which also means that the word will no longer have reference value - everyone is mixed, so it depends on what exactly is "mixed".