A comprehensive review of domestic brands’ hybrid technologies, four major mainstream hybrid configurations, which one truly represents the future?

Recently, BYD’s newly released fifth-generation DM technology has been very popular.

This technology is applied to the Qin L DM-i and Haibao 06 DM-i ( parameters | inquiry ) B-class cars, which can bring a comprehensive range of more than 2100km and a fuel consumption of 2.9L/100km when the battery is depleted.

There is no doubt that, driven by BYD, hybrid vehicles have ushered in a boom.

So, let’s review today the development history of hybrid technology of domestic car companies, and what are the characteristics of hybrid technology among major domestic brands.

First, P2 hybrid is the origin of China's hybrid technology

Before BYD released its fifth-generation DM technology, the brand gave us a "technology review".

In fact, BYD was the first car company in China to try out plug-in hybrids. In 2008, BYD developed the first generation of DM dual-mode hybrid technology and installed it on the F3 plug-in hybrid model.

In fact, BYD F3 DM dual-mode hybrid adopted the "classic" P2 hybrid architecture at the time.

The solution to this architecture is actually quite simple: add a drive motor between the engine and the gearbox. When the vehicle is driving, the motor can directly drive the gearbox, thus achieving "pure electric drive"; in hybrid mode, the motor can work simultaneously with the engine, thus reducing fuel consumption and improving performance.

Because the P2 hybrid configuration can be "modified" on the basis of a fuel vehicle by directly adding a motor and a drive battery, many car companies, including BYD, liked to use this configuration when they first launched plug-in hybrid products. At the same time, the actual effect brought by this hybrid configuration is also good.

For example, Changan’s iDD hybrid system is a P2 hybrid configuration, and its representative model is the Changan Oushang Z6 iDD.

This car has a 110kW drive motor placed between the 1.5T engine and the 6-speed "three-clutch gearbox". It not only provides a NEDC pure electric range of 150km, but also reduces the vehicle's comprehensive fuel consumption to 5.7L/100km under low-power conditions.

However, the P2 hybrid configuration is not perfect for family cars.

For example, because the motor takes up a lot of space, it is not very compatible with the transverse platform. Nowadays, many models built on the transverse platform have gradually abandoned the P2 hybrid. At present, only some off-road vehicles will adopt the P2 hybrid configuration; among them, the most representative one is the Hi4-T hybrid of the tank off-road.

Second, DHT hybrid has become the mainstream now

The so-called "DHT hybrid" is actually a relatively broad name.

At present, independent manufacturers such as Great Wall's Haval/Wei brand, BYD, Geely, and Chery have widely adopted the "DHT" hybrid configuration. Simply put, the DHT hybrid system will adopt a P1+P3 power structure, and the engine can achieve single-gear or multi-gear direct drive.

Taking BYD's latest fifth-generation DM technology as an example, the new DM-i hybrid system has the basic logic of generating electricity through the P1 motor, driving through the P3 motor, and adding the single-speed direct drive of the 1.5L engine, to achieve the four major driving modes of "series + parallel + direct drive + pure electric".

In series mode, the engine does not participate in driving, but only generates electricity for the battery through the P1 motor. The generated electricity directly drives the wheels through the P3 motor. In fact, this mode is somewhat similar to what we call extended-range drive.

In parallel mode, the engine and P3 motor drive the vehicle at the same time. This situation is generally used to meet driving scenarios with relatively high power requirements.

In direct drive mode, the engine directly drives the vehicle, and the vehicle generally travels smoothly and at a constant speed.

Finally, there is no need to say more about the pure electric driving mode. At this time, the engine is in a "dormant" state, and the P3 motor is driven by the vehicle's large battery. Take BYD's newly launched Qin L DM-i as an example. This car has a pure electric range of up to 120km under CLTC conditions.

Through the explanation of BYD's DM-i hybrid technology, I believe everyone has a clearer concept of the "DHT hybrid" configuration. In addition, many car companies pay more attention to "direct drive performance" when building DHT hybrids. In this regard, manufacturers such as Great Wall, Geely, and Chery have also specially built multi-gear DHT gearboxes for direct drive conditions.

For example, Great Wall's DHT-PHEV plug-in hybrid system adopts a 2-speed DHT gearbox design; Geely's DHT hybrid structure is matched with a 3-speed DHT gearbox; and Chery's C-DM hybrid system is also matched with a 2-speed gearbox.

The purpose of upgrading from "single-speed direct drive" to "multi-speed direct drive" is actually very simple, which is to save more fuel when the vehicle is cruising at high speed and expand the speed range of direct drive. For example, in the scenario of direct drive of plug-in hybrid vehicle, it is a fuel vehicle.

In this case, we can assume that the speed ratio of a single-speed direct drive is 0.8, and the engine speed is 2000rpm when cruising at 100Kph. The speed ratio range of a 3-speed DHT covers 1.1, 0.8, and 0.7. At low speeds, a multi-speed DHT can use a larger speed ratio to enter the engine direct drive condition in advance to avoid excessive power loss; and when cruising at 100kph, it enters the minimum speed ratio, and the speed may be only 1500rpm. In theory, a multi-speed DHT transmission will be more fuel-efficient at high speeds.

Third, extended-range hybrid, a representative of pragmatism

Among the current mainstream brands, we can never avoid the DHT hybrid mode. However, relatively speaking, the DHT hybrid technology is more difficult. Especially because the engine has a direct drive condition, it is necessary to perform complex matching and adjustment of the engine and gearbox (reducer). Therefore, in order to "save trouble" and "be convenient", some manufacturers will directly adopt the "simple and crude" extended-range hybrid.

For most consumers, the first extended-range hybrid brand we come into contact with is Ideal Auto.

From Ideal ONE to the current L series, all use extended-range power.

The working principle of the extended-range hybrid configuration is easy to understand. It adds a set of engines (range extenders) and generators to the pure electric basic platform to achieve "external charging".

From the perspective of technical principles, the extended-range drive is simple and reliable in structure, with a relatively low overall failure rate. At the same time, the vehicle is completely driven by the motor, and there will be no setbacks when switching between oil and electricity. However, relatively speaking, the motor consumes more energy under high-speed driving conditions. At this time, the charging power of the range extender is likely to not keep up with the power consumption of the motor, so there will be a certain loss of power under low-power conditions.

However, today, many mainstream automobile manufacturers will optimize the extended-range structure.

Taking DeepBlue Automobile, which is empowered by Changan technology, as an example, many models of this brand are equipped with extended-range power.

Take the Deep Blue S7 extended-range version as an example. This car is based on a 31.73kWh drive battery and can provide a CLTC pure electric range of 200km. In order to solve the problem of excessive energy consumption when the battery is low on power, Changan has also developed a new Blue Whale engine to "generate more electricity" with higher thermal efficiency. Its 1.5L range extender can generate 3.3kWh of electricity with only 1L of gasoline. When the vehicle is low on power, the comprehensive fuel consumption per 100 kilometers will not exceed 5L, and the fuel efficiency is comparable to that of the DHT hybrid configuration.

In fact, in general, the extended-range hybrid configuration, although the structure is relatively simple and the design difficulty is relatively low. However, it only needs to carry out targeted efficiency optimization of the range extender and drive motor to bring good performance and energy consumption performance to the whole vehicle. For consumers, the extended-range hybrid can be said to be very practical. For this reason, more and more manufacturers are currently investing their research and development work in the field of extended-range hybrid. For example, Lantu, Leapmotor, Nezha, and Changan Qiyuan have all launched extended-range technology and corresponding products.

Fourth, power split hybrid, derived from Toyota, stronger than Toyota

P2 hybrid, DHT hybrid, and extended-range hybrid are currently widely used by domestic brands. However, it should be noted that in the diversified market, there are still many domestic brands using hybrid configurations that we did not expect.

For example, the THS dual-engine hybrid system created by Toyota has completed the "hybrid enlightenment" in the automotive market.

Today, THS Hybrid has expanded from Toyota's single brand to more brands.

For example, GAC Trumpchi directly obtained Toyota's THS dual-engine hybrid system and applied it to products such as the second-generation Trumpchi GS8.

The THS dual-engine hybrid configuration is actually very cleverly designed: it uses a planetary gear set to fix the engine output shaft and the motor output shaft. In this way, it can achieve "power splitting".

That is: in starting or low-speed scenarios, the motor is used for driving; in acceleration scenarios, the motor and engine power are combined for driving; in high-speed scenarios, the engine is driven alone, and the remaining energy is used to charge the motor.