Text/Civil
The ultimate goal of hybrid vehicles is fuel saving, and the ultimate goal of pure electric vehicles is longer endurance. Hybrid vehicles can save fuel by switching modes, using fewer engines, and keeping engines in efficient economic ranges; pure electric vehicles can increase battery life by adding larger capacity batteries.
But the so-called open source throttling, only open source can not be, throttling is equally important. So how? This is what hybrid, pure electric models with motors are good at, they can achieve kinetic energy recovery through motors, charge the battery, in order to achieve the purpose of fuel saving and power saving.
What is kinetic energy recovery?
First of all, let's talk about the basic concept, the process of converting electrical energy into mechanical energy, known as electromagnetism, after the two magnetic fields are energized, they produce mutually exclusive or mutually attracting forces, so as to achieve motor operation; the motor can also act as a generator, the principle is the opposite, is electromagnetic induction, mechanical energy conversion process.
The application is actually when the driver releases the accelerator pedal, the motor does not act as a power source output, but acts as a generator, at this time the mechanical energy of the vehicle is converted into electrical energy by the generator and charged into the battery pack. When the generator is working, the two magnetic fields produce a certain torque, which is the opposite of the force output by the motor, which realizes the motor back-drag and makes the vehicle produce automatic effects.
How to improve the efficiency of kinetic energy recovery?
1. Simple superposition of brake energy recovery. That is, when the accelerator pedal and brake pedal are not stepped on, and the vehicle is in a taxiing state, the motor is used to give a braking torque to recover part of the energy. This method is the simplest and most reliable, but it is also the least efficient.
2. Compound braking. The braking force changes when the brake pedal is pressed, and in some cases it can be braked entirely by electricity, so more energy is recovered than simply superimposed braking energy. However, this configuration requires more ESP and needs to consider more functional safety issues, such as how to maintain braking force after the failure of the electric brake for some reason, and the coordination between the electric brake and the mechanical brake.
3. Single pedal control. It is an upgraded version of simple superimposed brake energy recovery. By setting a section of the throttle to deceleration control, such as loosening the throttle to 20% to start electric braking, more than 20% to start increasing braking force, controlled by the driver. This method is not technically difficult and the recycling efficiency is also high, but the control requirements for the driver will be higher.
No drawbacks to kinetic energy recovery?
First of all, the advantages are obvious: power saving, fuel saving; increasing the service life of the brake system; and strengthening the braking effect. But the disadvantages can not be ignored:
1, compared with the traditional fuel vehicles, new energy models with kinetic energy recovery systems will reduce speed faster, but some models will not light up in kinetic energy recovery mode, so there is a certain rear-end risk.
2. If the kinetic energy recovery effect is strong, the speed reduction will cause motion sickness among the passengers in the car.
3, if you are used to using the kinetic energy recovery mode for a long time to brake, you will habitually put your foot on the accelerator pedal, if there is an emergency, you may not be able to react at the first time, switch to the brake pedal, causing an accident.
4, the general battery power is higher than 90%, it will not be kinetic energy recovery, if you still habitually use kinetic energy recovery brake is also risky.
Recommendations for actual driving situations
Under normal circumstances, in the congested road section can use more high-intensity kinetic energy recovery, after all, has been braking, starting back and forth switching; in the smooth section can use low-intensity kinetic energy recovery, because generally only need to slow down, do not need to brake quickly, at this time low-intensity kinetic energy recovery experience is the best.
But in fact, the most fundamental is still based on their own driving habits and adaptation to determine, and the current car companies on the kinetic energy recovery of the adjustment are doing better, kinetic energy recovery system and mechanical braking system between the cooperation is very good, such as the driver does not need to brake vigorously, only kinetic energy recovery intervention, when the vehicle needs greater braking force, kinetic energy recovery full load recovery, and mechanical braking intervention.
If you have never been in contact with a driver who has a kinetic energy recovery model, you must start to adapt from the minimum kinetic energy recovery mode, after all, it is quite different from the traditional fuel vehicle. But now with the continuous development of new energy vehicles, the corresponding kinetic energy recovery system of each car company is more comprehensive and perfect, and the experience is getting better and better, and there will be no problems such as abrupt system intervention, non-linearity, and logical confusion, and the experience of fuel vehicles can be achieved or even surpassed.
summary:
Kinetic energy recovery is that the mechanical energy of the vehicle is converted into electrical energy by the motor to charge the battery, so as to achieve the purpose of fuel saving, power saving, increasing endurance and assisting braking. The disadvantage is that compared with the traditional fuel vehicle brake, there will be some safety hazards and experience problems. Although the kinetic energy recovery system is now well tuned, the driver still can't rely too much on this function, after all, the simplest brake is the most reliable.