Source | All Electric (ID:GeekNEV)
Author | Luo Shunpeng
Since its birth, the 48V mild mixing system, which has been criticized, has been favored by luxury brands such as BBA and Cadillac.
Source: Pexels
In August this year, the new generation of Mercedes-Benz C-class was officially launched, in a clamor of gongs and drums, another kind of spit questioning voice after another, are about to sell to 400,000 cars, and the whole series is only equipped with a 1.5T engine, forehead, no, a set of 1.5T engine + 48V motor light hybrid power system.
However, this kind of doubt was quickly replaced by the sales of the new C-class, whether to sell or sell, Mercedes-Benz C-class sold nearly 13,000 vehicles in October...
Then, do you think that this article is going to turn on spit mode and spit on the new C-level? And slowly, we turn our attention to the above-mentioned 48V mix system, saying that this light mix system seems to have been spat upon since the beginning of its birth, but it has been favored by some manufacturers, a real hammer integrated contradiction of the automotive industry technology
Regarding the 48V light mix, people who advocate it say that this is a downgrade artifact, and it can also improve the smoothness of power, why not; people who complain think that this technology has little practical effect at all, and is only a folk remedy for manufacturers to reduce costs.
The debate about this technology is endless, and today Diange tried to talk about this controversial technology in detail for everyone.
Light mix ≠ hybrid?
Regarding the definition of this light mix, in a narrow sense, the hybrid we mention every day does not actually count the form of light mixing, and the hybrid we more often refer to is like the oil-electric hybrid promoted by the Japanese brand and the plug-in hybrid technology that everyone is doing.
But if it is defined from the direction of whether the motor is involved in the power output link, it should indeed be classified as a hybrid. In the industry, we usually divide hybrid vehicles into light mixing and heavy mixing according to the proportion of power of the electric motor. Light mix for the motor power accounted for less than 10%, simply put, the motor in the power output of this piece only plays an auxiliary role, representative models have Mercedes-Benz C-class, Audi A8L, WEY mocha, as well as is the new car of the universal system, etc. (here need to draw the focus, light mix in addition to domestic brands, are some American, European brands in use, the reason for the later analysis of the group).
The motor power of the remix accounts for more than 25%, which represents toyota dual engine products such as the hybrid originator Prius, Honda sharp hybrid products, and domestic pride BYD super hybrid dmi related models.
We often say that the hybrid technology is represented by the two fields, and their advantages are clear to everyone, so that the engine can maintain a higher efficiency range, the purpose is to reduce fuel consumption. The specific introduction of oil-electric hybrid technology will not be discussed in detail, after all, this article is still mainly concerned about 48V light mixing technology.
The role of 48V light mixing is more used to drive the non-power output of large electrical components on the car, reducing the engine load, so that the engine can focus more on its own work, theoretically can improve the working conditions of the engine, but in fact, let's take an immature example:
The 2018 Mercedes-Benz C-Class C200L (2.0T) NEDC has a combined fuel consumption of 6.3L/100km and an acceleration time of 7.9s from 0-100km/h
The 2022 Mercedes-Benz C-Class (replacement) (1.5T light hybrid) NEDC has a comprehensive fuel consumption of 6.35L/100km and an acceleration time of 7.7s from 0-100km/h
Then some people will ask, then this is not very significant to consumers, why do everyone have to push this technology?
One is the emission standard, and the other is helpless.
Why are you all here to join in the fun
Continuing with the topic just talked about, to be honest, 48V light mix is a stopgap measure, not that they have to do it, but as a last resort.
Why?
As we all know, Europe, North America parts of the emission standards are strict, each emission standard update in addition to bringing better air quality, but also so that many car companies collapse, and after entering the 21st century, the update of emission standards has become more and more frequent, a few years a more standard, so that many car companies can not timely develop and produce products that meet the new standards.
So what to do?
Add a variety of equipment to the original product to reduce emissions! Particle traps, three-way catalysts, etc. are arranged, but I can't eat hot tofu in a hurry, what if I don't match? It will not cause the previous well-known brand particle trap to block, and small problems will occur frequently.
In addition to these methods, some car companies have thought of adding motors to form a light mix to deal with it, and the light mix set finds suppliers to supply a set of up to a few thousand pieces. The common 48V light hybrid solution, in addition to better avoiding the phenomenon of turbo lag that can be detected by turbocharged engines, can match a series of transmissions such as transmissions and differentials to the engine, so that the engine runs at a lower speed per minute under the established highway conditions. For example, when the car accelerates and climbs, after using the 48V light mix system, there is no need to downshift, and it can directly provide more torque at high gear and low speed, thus realizing the low speed of the engine to reduce fuel consumption and emissions. (Of course this is just theory)
Seeing this, some small partners will definitely have questions, since light mixing is only a stopgap measure, why do a number of European and American manufacturers not learn from Japanese car companies to engage in oil-electric hybrid?
The reason is very simple, the core technology related to oil-electric hybrid is mastered in the hands of several Japanese brands, and it cannot be used!
According to the energy connection method, the oil-electric hybrid is divided into three types: series, parallel and mixed. Parallel is relatively rare, mixed most of the core technology patents are in the hands of Toyota, that is, we often say that the dual engine technology, Honda went to the series hybrid, on the sharp hybrid. Let's say that if other manufacturers want to break through this layer of technical barriers, they will either choose to cooperate with Liangtian (such as GAC), or avoid some core technologies to find solutions (such as the Great Wall), or use other technologies to replace (such as Nissan's e-POWER technology, which is actually a range extender technology), but in either way, the input cost is not small, it is better to find a supplier to have a light mixed suit that can be used without how to match, which saves trouble.
After saying that for so long, what is 48V light mixing and why it is necessary to use light mixing are basically clear, and then we will talk about the characteristics of this technology.
Why does it have to be 48V?
Before introducing the characteristics of 48V light mix technology, we must first give everyone a knowledge point, that is, why is it not 12V, not 220V, but 48V, everyone is so obedient to the rules?
The thing is this, since the motor to participate in the power supply, the output power is equal to the voltage at both ends of the motor multiplied by the current flowing through the motor (P = UI), the motor to achieve a large enough output power, if you rely solely on the original 12V voltage on the car, the current to reach the same level of 48V, to 4 times the current size, at this time the loss of the wire, the heat must also be taken into account, the wire loss = wire resistance multiplied by the current. And why not blindly use a larger voltage is simpler, if the voltage is large enough, it is better to make a plug and mix. In addition, 48V is just below the 50V required for safe voltage, so everyone defaults to 48V as the voltage value of light mixing.
To go deeper, 48V light mix according to the different motors can be divided into BSG and ISG two forms, the same point is that the vehicle is equipped with a set of 48V motor system, to power other electrical systems on the car, reduce the engine load, while at the engine start, through the more powerful 48V motor to make the engine quickly reach the idle speed, shorten the starting time; when stopping, the engine can be turned off in advance, the use of motor drag system operation, thereby improving fuel consumption and form smoothness. At the same time, during deceleration and parking, power generation can be generated by wheel anti-tractor motors, and the electrical energy is stored in a 48V lithium battery.
The two principles differ in that:
BSG motor
The full name of the BSG motor is The Belt-Driven Starter Generator, which is an all-in-one machine that uses belt drive to take into account both starting and generating electricity. That is, as its name motor is mainly responsible for starting, in the P0 area layout of the car, in this form, usually retain the 12V power supply, and in the 48V battery system to add a DC / DC converter, converted to 12V, for the 12V battery power.
The use of BSG motor, the motor is mainly for the engine start as an auxiliary, can make the main vehicle run more smoothly, reduce emissions, but because the transmission efficiency of the belt is low, the actual power output of the vehicle is not much help, better than the low cost, most of the light hybrid models on sale at this stage are using this form.
ISG motors
ISG motor full name Integral Starter and Generator, Chinese translated as the car starter power generation integrated machine, the motor is arranged in the position of P1, that is, between the engine and the transmission, specifically integrated in the engine crankshaft, directly with a certain transient power of the motor instead of the traditional starting motor, in the initial stage of short-term replacement of the engine to drive the car, and at the same time play the role of starting the engine, reduce the idle loss and pollution of the engine.
During the driving process, when the engine alone outputs power, the motor is disconnected or generates electricity, and when the driver needs the vehicle to accelerate sharply, the motor can be used as an auxiliary power output source to enhance the power output of the vehicle. At the same time, ISG motors can also play an energy recovery effect when the vehicle is braking.
The meaning of light mixing
The meaning of light mixing is "light", but this is also doomed to it can not be like oil-electric hybrid or plug-in hybrid, the motor can play a role in driving the vehicle alone, whether from the actual effect, or the driver experience, the change brought by light mixing is not too big, at best can only make your vehicle ride smoothness get a slight improvement.
For any hybrid technology, whether it is a weak mix, a strong mix, or a plug-in mix, the ultimate goal is to reduce carbon emissions. Light mixing is too small in the proportion of electrical energy, the actual impact on carbon emissions is not obvious, if you really want to have a real electric energy experience, it is still recommended that you choose a power system with a larger proportion of electrical energy.
In general, 48V light mix is not a scam, it still has a role, but the role is not so big as advertised, many manufacturers do not even take it for this reason.