Danfoss Motor- Future Car Power System Development Trend
Danfoss Motor and everyone will discuss how the future car’s power system will develop.
The car has been developed for more than 100 years. The main power is the internal combustion motor, which is divided into gasoline motor, diesel motor and gas motor. These power systems play multiple roles in different fields. Gasoline motors are mainly used for passenger cars, which are cars, SUVs, etc. that are usually opened, and have the characteristics of light weight and low noise. Diesel motors are used in a wide range of applications, from passenger cars (mainly in Europe), commercial vehicles (tractors, trucks, etc.) to yachts, ships, generators, agricultural machinery and other industrial fields. Diesel motors are characterized by high torque, high horsepower, heavy weight, high noise, and large displacement. Large-displacement diesel motors can have thousands of horsepower and hundreds of thousands of liters of displacement, which are used to push the giant wheels forward. Gas motors also have a place in the commercial sector.
When we focus on the automotive sector, we can see that in the past five years, various forms of power systems have been continuously introduced to the market. The reason is that the emission regulations are tightened and the energy requirements are constantly increasing, so that the motor is not only cleaner, but also more efficient, thus forcing the motor to continuously improve the thermal efficiency. The thermal efficiency of gasoline motors has exceeded 40%, and this figure is already the limit that mass production technology can achieve. Diesel motors are approaching 50%, which is the limit that existing mass production technologies can achieve. Mazda announced that the new generation of Chuangchi blue sky gasoline motor is expected to break through 50%, fuel consumption is as low as 3.5 liters per 100 kilometers. This is an exciting news, let us wait and see.
Our country’s internal combustion motor industry started late, and the parts and components industry chain technology is backward. In the traditional internal combustion motor business, it may take decades to hone in order to approach and surpass the old-class internal combustion motor opponents. The country is considering promoting new energy vehicles, and it is expected to achieve overtaking on corners at similar starting lines. Of course, national energy security is also one of the considerations for promoting new energy vehicles. With the addition of new energy vehicles, the total power of the car has been enriched. The motor also ushered in a new round of changes. The depth of our intervention from electrification, from shallow to deep.
The motor is naturally aspirated for a long time. So at that time, the motor displacement was large, the power was small, and the motor with four-liter displacement could not even reach the power of the current 2.0T motor. So far, turbocharged motors (motors with T) have dramatically replaced traditional naturally aspirated motors. Thanks to the turbocharged system, the motor can output a large amount of power with a small displacement, and the fuel consumption will be further reduced under certain working conditions. The last change in the motor was supercharging. Under the trend of new energy, I think the next revolution of the motor is electrification. Just like everyone is used to talking about the motor, it is said that it is turbocharged. In the future, everyone will say that the motor is charged.
The electrification of the motor has different depths, which are also called hybrid types depending on the depth of electrification. In fact, * slight motor electrification (micro hybrid MicroHybrid) is already in use, that is, the motor start-stop system (start-stop). This is based on the voltage of the original motor (the passenger car is generally 12V), using a starter motor or accumulator to stop the motor when waiting for a red light or a short time to achieve fuel-saving purposes. Of course, Mazda’s start and stop is another principle, which is not detailed here. Since the voltage is not high, the starting power is not large, and the battery capacity is not large, so everyone will find that the motor is not stopped for a long time, and if the operation is not good, the startup process is quite annoying.
In order to further reduce fuel consumption and make the motor stop longer, European manufacturers began developing the 48V light mixing system (MildHybird) in 2013. The significance of the 48V light-mixing system* core is that its added cost is not high, mostly only a few thousand dollars, and save fuel more than micro-mix, about 6-15%. Since the 48V system’s *high voltage 54V is lower than the European ECER100’s DC voltage of 60V, no additional protective measures are required. And the modification of the whole vehicle is small, mainly concentrated on the motor, and the research and development cost is low, which is a cost-effective solution. The increased voltage can drive a more powerful starter, and can use a larger capacity battery (less than 1kwh, much less than the power battery capacity of a new energy vehicle). Parts suppliers have developed BSG and ISG, which can be installed at the front end of the motor. And the back end, used to start and power the motor. Its assist torque range is 40Nm to 250Nm. Limited by voltage, its duration is not long and power is not high. Having said that, the role of the 48V system is said to be more than half.
To sum up, 48V has the following effects:
1. Increase the motor starting speed (0.2-0.4S, 0.5-1s for ordinary motors) and extend the motor stall time. It can be turned off at a speed of 20Km/h or even when the highway is downhill. Do not do this for ordinary motors, because the steering and braking are in a state of failure after the motor is turned off. But the 48V motor starts very fast, so the motor will start instantly when needed, providing the vacuum of the brakes. The 48V vehicle steering gear is also electrically powered. If steering is required, sufficient power is supplied from the battery to assist steering during motor stall.
2. The air conditioner can continue to be used after the motor is turned off, because it has been changed to electric air conditioner. The air conditioning of an ordinary vehicle is driven by an motor belt to drive an air conditioner compressor. The air conditioner of a 48V vehicle is electrically driven, like an electric vehicle. Therefore, there is no case that the air conditioner cannot be cooled when the start-stop system is started.
Hybrid (whether 48V light mix or PHEV plug-in hybrid / HEV strong mix) is a transition technology, the future goal must be pure electric and fuel cells. But this transition time will be very long. It is predicted that by 2050, at least 50% of the vehicles will be equipped with internal combustion motors. This transition time may depend on the development of pure electric or fuel cells. If one of the two develops explosively, the internal combustion motor may soon die out. So no one can say how long it will be a transition. Therefore, hybrid technology is still the place where major manufacturers exert their strength. In the PHEV/HEV phase, the motor can be used as a power source or as a charging source, so the form of the motor has begun to diversify. If it is focused on the power-up upgrade PHEV model, it will still be equipped with a high-power turbocharged motor, in order to obtain better vehicle dynamics. If it is fuel-saving, the motor needs to be improved, and the Atkinson cycle is taken at low and medium loads to improve fuel economy. Toyota’s HEV is an example. Due to policy-driven and patent restrictions, Chinese brands mostly focus on the development of PHEVs. Compared with HEV, the fuel consumption of PHEV technology is easy to achieve 2L/100km, and the new one has already achieved 1L/100km. However, everyone knows that this is the first 100km. When the battery is used up more than 100km, the fuel consumption will soar. No one can say that HEV/PHEV is better. I think it is only necessary to choose according to your own working conditions and charging convenience. At present, most of the PHEVs are still used in conventional internal combustion motors, and these internal combustion motors are also used in non-hybrid models.
Professionals believe that these internal combustion motors will also be improved in the future, and the motor electrification will continue to be promoted. There will be fewer and fewer accessories on the motor, and more accessories will be powered directly by electricity. The number of electronic control components on the motor will also increase, further reducing the resistance power of different working conditions. Improvements to the combustion process rely on the Atkinson cycle to continually optimize, driving the gasoline motor toward 45% thermal efficiency, and the diesel motor moving toward 50% thermal efficiency. There are still many things that can be done in the internal combustion motor, and the electric vehicle is also developing rapidly at the same time. It can be foreseen that there will be multiple technologies in parallel for a long time, and consumers can also select the corresponding technology vehicles according to their own needs.