What is the principle of 48V light-hybrid system, which is used as a gimmick by automakers every day?

What is the principle behind the 48V light-hybrid system that has been used as a gimmick by automakers every day?

In the new energy policy support, pure electric models more and more, but with the current technology, it is difficult to reach the degree of fuel vehicles in a short period of time, so the hybrid models have become a good choice, not only to ensure the convenience of daily use of the car, but also to achieve energy saving. Hybrid system, in fact, is just a general term, generally subdivided into four forms of hybrid, plug-in hybrid, light hybrid and add city.

Today, we will talk about the recent hot 48-volt light hybrid system, including Volkswagen, BMW, Mercedes-Benz, Geely and other car companies have begun to use this technology in new models. The core components of the mainstream 48-volt light hybrid system include a 48-volt battery, a starter motor, a voltage inverter, and a corresponding control module. The 48-volt batteries, mostly lithium-ion batteries, not only support fast charging capability, but also can effectively control the volume, will not take up the car to defend the layout space. At the same time, 48-volt voltage can meet the requirements of lithium-ion batteries to quickly realize the energy recovery, so as to achieve the role of reducing fuel consumption and exhaust emissions. Why must it be 48 volts?

Currently the mainstream car battery voltage is 12 volts, but the traditional 12-volt capacity is very limited, can not afford to take very high power electric equipment, want to realize more of the tiresome operation to increase the voltage. The reason why 48 volts is not higher is because according to European regulations, DC voltage of 60 volts and AC voltage of 30 volts or less is a safe voltage, which will not cause personal injury. 48-volt powertrain system maximum voltage is generally about 54 volts, which is just within the range of safe voltage.

There's also the issue of cost. Using 48-volt light-hybrid technology will only add about $5,000 to the cost of a car, compared with an additional $25,000 if heavy-hybrid technology is used. But the savings aren't going to be a five-fold increase, so in aggregate, light hybrids can achieve the greatest results with the smallest investment. While the 48-volt motor can't drive the vehicle alone, its most important role is to take some of the strain off the engine when the car is most fuel-intensive. Especially during startup and acceleration, the light-hybrid system's electric motor steps in to work with the engine, increasing power while reducing fuel consumption and exhaust emissions.

The 48-volt light-hybrid systems of some automakers have even more features, such as Mercedes-Benz's RSG technology motor, which delivers 166 meters of torque at the moment of ignition, quickly pulling the engine up to start-up speed in 380 milliseconds and with virtually no vibration. During the car's acceleration phase, the motor provides an additional ten kilowatts of boost to make the pickup even faster, while the motor delivers boost torque with each gear change to help the engine reach its target rpm as quickly as possible. And in the case of sufficient power, the motor can also maintain the cruising speed, the engine will war off, such as when closing the throttle coasting, the motor will intervene, output a very small power, you can maintain the current speed of the vehicle, this time the engine will automatically shut off, when step on the gas pedal, the engine will be restarted, continue to drive the vehicle forward.

In short, the basic idea of the 48-volt light-rail system is actually to increase the standard voltage of the vehicle's equipment to 48 volts by making it capable of driving higher-power on-board systems and realizing better integration of other systems on the vehicle. And its biggest benefit is to provide assistance in engine start/stop, starting, accelerating, coasting, braking and other working conditions, ultimately realizing energy saving and environmental protection. Therefore, it is also used as a bridge between traditional and new energy vehicles, or excessive.