Text/Civil
According to Honda's sales data for 2021, the cumulative sales of its models equipped with hybrid systems for the whole year are 233,801 units, which is inseparable from Toyota, which is also a Japanese brand, since it comes from the same country and is a pioneer in hybrid technology, how is Honda's hybrid system different, can it compete with Toyota? Cheaper or more fuel efficient? It's worth analyzing.
Toyota from 1997 when the first launch of the THS hybrid system, through the patent application, the system based on the planetary gear set firmly in their own hands, limiting the development of hybrid technology of many other car companies, then as an old rival Honda wants to bypass Toyota's patented technology to do hybrid technology, it is a big test.
Honda had already launched a weak hybrid system IMA (Integrated Motor Assist) in 1999, but due to the small battery power and motor power, it could not achieve full motor drive, so the fuel consumption and NVH performance were significantly worse.
Finally, Honda introduced the i-MMD (intelligent Multi-Mode Drive) hybrid system in 2013. The overall performance is not inferior to Toyota THS, and the two go hand in hand again.
The i-MMD system consists of an internal combustion engine and two electric motors. The engine and motor are coupled by ordinary gears. Conversion in series and parallel is achieved by means of clutches. When the clutch is separated, the engine and drive motor of the i-MMD are in series mode, the engine rotates to drive the generator to charge, and the electric energy drives the motor to rotate to drive the wheel to run.
When the clutch is combined and the generator is disconnected, the engine and the motor become parallel mode, at which point the power of the engine and the motor can be transmitted to the drive shaft together through different reduction ratios. Direct engine drive is also possible.
Specifically, the working modes of the i-MMD hybrid system are as follows:
1. Pure electric mode
In this mode, it is a purely electric drive mode that is powered by the battery. In this mode the engine does not work, the generator does not work, the clutch is disconnected, and only the power battery provides power to the drive motor. This mode is suitable for starting and low speed and low load conditions.
2. Hybrid drive mode
In this mode, the engine drives the generator to generate electricity, and then directly supplies power to the drive motor to drive the vehicle, which is suitable for high load, rapid acceleration and other working conditions. At this time, according to the charge and discharge state of the battery, it can also be subdivided into charging mode and auxiliary mode.
(1) The charging mode is to drive the motor load is larger, but there is no need for the battery and the engine to be powered at the same time, at this time the system will start the engine, adjust to the most efficient operating range according to the current state, and then drive the generator to generate electricity, the power generated by the generator is directly to the drive motor for power supply, and the surplus electrical energy will be fed back to the battery for charging.
(2) Auxiliary mode is in the case of rapid acceleration, the engine drives the generator to generate electricity, and the electrical energy emitted by the generator is all used to power the driving motor, and the battery is also added to power the driving motor, and the full power of the driving motor is exerted.
3. Engine drive mode
In direct engine drive mode, the clutch plates are coupled and the power of the engine is transmitted directly to the drive wheels through mechanical transmission. However, the trigger range of this mode is relatively small, and it is only turned on during high speed and low load (high speed cruise).
4. Kinetic energy recovery mode
In situations such as deceleration, braking or downhill, the engine and generator stop working, and the drive motor rotates in reverse to generate electricity to charge the battery.
The Honda i-MMD hybrid system has now been updated to the third generation, but the overall structure has not changed, the second generation reduces weight, size and complexity compared to the first generation, improving efficiency; the third generation has optimized the 2.0 L Atkinson cycle engine compared to the second generation, so that the thermal efficiency of the engine has reached 40.6% (38.9% of the previous generation), and the intelligent power unit (IPU) is 32% less in volume than the previous generation, while using a magnet motor without heavy rare earths.
Overall, Honda's i-MMD hybrid system is actually more inclined to a pure electric model, the motor is the main force driving the vehicle, so in terms of fuel consumption and other aspects will be lower because of the proximity to electric vehicles? By collecting information provided by car owners online, we have come to the following conclusions:
Taking the Accord Hybrid Edition as an example, through data collection, the comprehensive fuel consumption of each car owner is integrated, and its fuel consumption of 100 kilometers is about 5L, if it is only in the urban area or uses the economic model, it will be significantly reduced or even lower than 4L.
How does it compare to Toyota? We take the Toyota Camry as an example, its comprehensive fuel consumption is also about 5L, depending on the driving habits may fluctuate up and down about 0.4L, the difference in fuel consumption between the two is not obvious.
Continue to compare the driving experience, in the case of low speed, Toyota is mostly the state of the engine and the motor driven together, so the overall power output is relatively smooth, the fuel saving effect is also better, the planetary gear is slightly better than the E-CVT, the stability is also slightly better; in the medium and high-speed working conditions, Honda has an engine direct drive, so the power loss is smaller, and the power is stronger than that of Toyota.
summary:
The Honda i-MMD hybrid system is a typical series-parallel structure, in addition to pure electric, hybrid drive. Compared with Toyota, it has increased the engine direct drive mode, which has an advantage in terms of power, while Toyota is slightly better in terms of smoothness and fuel consumption at low and medium speeds. In terms of fuel saving, the two have not opened the gap, and the technical principles are different, so there is no distinction between high and low, and consumers can choose according to their own situation.