Planetary Gear Hybrid Power System (THS) is also known as the most mature hybrid power system. The planetary gear power split system is not difficult, but Toyota applied for a patent more than 20 years ago.
In the meantime, the hybrid system developed by other car companies can't directly adopt the planetary gear hybrid system, so we can only find ways to bypass it, such as adding an extra planetary row. Yuan Keli once developed such a hybrid power system (CHS), but the internal friction of the system increased, there was no efficient Atkinson cycle engine, and the electromechanical technology was backward. After the prototype car was trial-produced by Toyota and Geely Emgrand, it was found that the fuel consumption per 100 kilometers was about 1 liter higher than that of Toyota. So you don't have to arrange production. It can be seen that CHS hybrid is not an original research, but an additional planetary row to avoid patents, and its working principle is almost close to THS.
In fact, there is an automobile manufacturer in China, and the hybrid system developed by Honda is somewhat similar to Honda's IMMD hybrid.
Honda's IMMD hybrid I believe everyone knows its working principle, as shown in the following figure:
Honda is still held hostage by patents, so it can't use planetary gear hybrid power. However, Honda developed the IMMD hybrid system with its own strength. The principle is simple and ingenious. With the help of two motors and a clutch, the oil-electric hybrid is completed, and the medium and high-speed fuel consumption performance is better than Toyota's THS hybrid. At medium and low speeds, it is completely driven by a motor, and the generator is used to generate electricity. At high speed, the engine directly drives the wheels through the clutch. This system is widely used in Honda cars/SUVs/MPVs. It is the most important power system of Honda and will be widely promoted in the future. I remember that Honda's IMMD hybrid came out in 20 12.
Next is the first brother of domestic hybrid car: BYD.
Needless to say, BYD is the pioneer of new energy vehicles. BYD introduced the F3DM model in 2008, which is also the first generation hybrid car of BYD. Look directly at the schematic diagram of F3DM:
In HEV mode, the engine drives M 1 to generate electricity, charges the battery, supplies power to M2 motor, and the clutch is disconnected. At this time, the vehicle is driven by the motor. In electric mode, the vehicle is driven by M2 motor alone. When the battery is 20% low, start the engine to charge the battery. When accelerating rapidly, the clutch combined with M 1M2 is connected in parallel with the engine to jointly drive the vehicle.
But at that time, BYD's focus was on the battery, and the main idea was to use large-capacity batteries to achieve longer battery life. The engine is just a range extender/generator here, and its starting point for developing hybrid is plug-in hybrid and betting on plug-in hybrid. After all, plug-in hybrid is easy to break through the low fuel consumption of oil-electric hybrid with the cooperation of large-capacity batteries.
BYD, on the other hand, was born in electronic technology and started as a battery, providing lithium batteries for many mobile phone manufacturers. And what is BYD's bet on plug-in hybrid? Iron battery? , namely lithium iron phosphate battery. After the mass production of large-capacity iron battery pack was successful, BYD's confidence in plug-in and plug-in hybrid power became more firm. At that time, Toyota's hybrid system was like a mountain, insurmountable. At that time, BYD was not involved in building cars for a long time. In the field of fuel vehicles, both the engine and gearbox/chassis are in the stage of learning and development, and there is no strength to compete with Toyota. BYD also knows its own shortcomings, so it never thought about building a hybrid system. At that time, other domestic brands were in the same situation. Everyone is just starting, and they haven't even learned how to build a good car. In this case, the research and development of hybrid vehicles is naturally more backward, with the focus on fuel vehicles.
F3DM is very close to Honda's IMMD hybrid system.
BYD introduced the DM model, and Honda released the IMMD hybrid technology four years later. Then why doesn't F3DM have a fire? In fact, the first generation DM models still have many shortcomings, such as poor power and poor driving experience. Let's take a look at the configuration table of F3DM:
Several key data: three-cylinder 1.0L displacement engine, 25kw generator and 50kw motor. This is the root of poor performance of motivation. The power of the engine and motor is too small, so the engine can't provide enough power to drive the vehicle in HEV mode, and the driving experience is naturally much worse. The engine power is insufficient, and the power generation is small, so it is naturally difficult to eat enough for the driving motor. With this power configuration, the driving experience will not be very good, especially after power loss.
Honda's IMMD hybrid system performs better than Toyota's THS system. Let's compare the differences between Honda and BYD:
It can be seen that the mixing principle of motor and clutch is almost the same except that the layout of motor and clutch is different and the battery capacity is different.
● Both are series hybrid power, and the engine is used to generate electricity or directly drive the vehicle.
● In order to improve power/driving experience/reduce fuel consumption, Honda's approach is different from BYD's. For example, using 2.0L Atkinson cycle engine, the thermal efficiency is as high as 40.6%.
● At the same time, 135kw drive motor is adopted, with the maximum torque of 3 15Nm. The engine has enough power to drive the generator, and the motor can also eat enough, so the vehicle has good dynamic performance in series mode.
● The dynamic performance/comfort of the large displacement engine at high speed cruising is also obviously stronger than that of the small displacement three-cylinder engine.
The reason why BYD didn't achieve the results similar to Honda's hybrid is completely caused by the different starting points. At that time, Toyota's hybrid was the only one, and it was unrealistic to engage in hybrid oil and electricity. After all, the problem of food and clothing for everyone (all domestic automobile manufacturers) has not been solved, and the research and development of fuel vehicles still has a long way to go. Naturally, there is no time to develop hybrid cars.