Decoding the "50% fuel saving" technology: Great Wall Motors' Lemon Hybrid DHT is disassembled for the first time in the world

On March 2, 2021, Great Wall Motors conducted the world's first live disassembly of the Lemon Hybrid DHT. This is also the first time that the Lemon Hybrid DHT has been disassembled online since its global debut in December last year.

Lemon Hybrid DHT World's First Disassembly Live

Song Dongxian, Vice President of Technology of Great Wall Motors, Shuai Shijin, Professor of the State Key Laboratory of Automotive Safety and Energy Conservation of Tsinghua University, and Xia Dong, a senior automotive media person and founder of KickCheBang, attended the live broadcast together. They not only broke down and interpreted the overall design of the Lemon Hybrid DHT by module, but also made wonderful sharing on its technical advantages, working principles and user experience, and comprehensively analyzed the secret of the Lemon Hybrid DHT's excellent performance.

Hybrid technology is an important support for Great Wall Motors' globalization

Shuai Shijin (center), Xia Dong (left) and Song Dongxian (right) discuss hybrid technology in depth

Before the formal disassembly, several guests first shared their basic views on hybrid vehicles. Professor Shuai Shijin believes that the "Energy-Saving and New Energy Vehicle Technology Roadmap 2.0" points out the necessity of developing hybrid vehicles, and hybrid vehicles will become the dominant force in travel for a long time.

Shuai Shijin (left) and Xia Dong (right) comment on the hybrid technology route

Xia Dong, based on user needs, put forward the view that "hybrid vehicles are closer to fuel vehicles and are the technology that best meets user needs at present", expressing his recognition of hybrid vehicles.

Song Dongxian (center), Vice President of Technology at Great Wall Motors, introduces the technical features of Lemon Hybrid DHT

As Vice President of Technology of Great Wall Motors, Song Dongxian explained the significance of Great Wall Motors' development of hybrid vehicles. He said: "A single technology route cannot solve all travel needs. Great Wall Motors wants to compete globally and meet the diversified needs of global users. Hybrid vehicles are an important technical support."

Lemon Hybrid DHT's powerful software and hardware are the foundation for excellent performance

As a hybrid technology that can achieve both excellent performance and efficiency in all speed ranges and all scenarios, the entire system architecture of Lemon Hybrid DHT can be summarized as "1-2-3", that is, a DHT highly integrated oil-electric hybrid system, two power architectures of HEV/PHEV, and three powertrains for different levels of vehicles.

Lemon Hybrid DHT Assembly

In terms of design structure, the Lemon Hybrid DHT has the following key components: 1.5L/1.5T hybrid-specific engine, dual-motor controller, DHT module, and high-specification power battery.

1.5L/1.5T hybrid dedicated engine, the former has a maximum power of 75kW, matched with a 100kW DHT module, and a system comprehensive power of 140-170kW; the latter has a maximum power of 115kW, matched with a 130kW DHT module, and a system comprehensive power of 180-240kW. The live broadcast shows the 1.5L engine, which uses Atkinson cycle, external water-cooled EGR and other technologies, with a compression ratio of up to 13:1, and has undergone a reliability verification of up to 3,000 hours, which is efficient and ensures the reliability of system operation.

Dual Motor Controller

The dual-motor controller can be described as the "central brain" of the Lemon Hybrid DHT. It is the first in the industry to be equipped with a new generation of high-computing power Infineon TC38 series processor chips, which have strong computing power and high reliability. Combined with the control algorithm independently developed by Great Wall Motors, it can achieve scientific and reasonable control of the energy flow of the system.

DHT Module

The DHT module can be understood as the "transmission device" of the Lemon Hybrid DHT, which includes a reducer, a clutch, a shift mechanism, and dual motors. It adopts a dual electronic pump design, which can adjust the start and stop of the electronic pump based on the needs of the vehicle; it adopts a single clutch design, which has lower lubrication and cooling requirements than a dual clutch. And it is very compact in structure, which is more than 50% lower than the traditional DCT.

Dual motors

In the DHT module, the dual motors themselves are also crucial. The motor adopts the high reluctance torque design concept, which reduces the amount of magnetic steel by more than 20% compared with the ordinary permanent magnet motor design, achieving the purpose of lightweight; the hairpin flat wire design, the slot fill rate is as high as more than 70%, effectively improving the power density of the motor; the short-pitch winding arrangement optimizes the air gap harmonics, reduces the electromagnetic force of each order, improves the 48th and 96th order high-frequency noise, and the NVH performance is first-class in the industry; low-loss 0.27mm silicon steel sheet, iron loss is reduced by more than 17%, achieving a double 85% high-efficiency area share.

High-specification power batteries are also core components of Lemon Hybrid DHT. Taking the power battery of the PHEV architecture four-wheel drive model as an example, its energy density exceeds 160Wh/kg, which can provide a pure electric range of up to 200km. In terms of charging and discharging, it supports 11kW AC charging power and DC fast charging, can charge 80% in 30 minutes, and has a maximum discharge power of 246kW, with an 8-year and 150,000-kilometer warranty.

Great Wall Motors' Lemon Hybrid DHT will soon be used by WEY's new compact SUV

With powerful software and hardware as the cornerstone, Lemon Hybrid DHT has more working modes to cope with different road conditions and scenarios.

Pure electric driving mode

Pure electric drive and series drive are driven by the motor, and the engine does not work or is only responsible for "generating electricity". They are mainly used for driving at medium and low speeds and stop-and-go conditions. This can give full play to the advantages of the motor's high efficiency and quick response, allowing the engine to operate in the best fuel efficiency range and improve fuel economy.

Engine direct drive mode

Engine direct drive is mainly used in urban ring roads, highways and other scenarios. Under relatively "steady-state" road conditions, the comprehensive efficiency of engine direct drive exceeds that of series drive, which can save 10%-15% fuel. In addition, engine direct drive has optional economic gear and power gear, which can respectively cope with smooth cruising and mid-distance acceleration, achieving a "gear shifting" effect similar to that of fuel vehicles, perfectly combining power and economy.

Parallel drive is mainly used to deal with short-term high-load rapid acceleration. To avoid excessive load on the engine itself, the motor provides additional power support and works together with the engine to maximize power.

Energy recovery mode

Energy recovery: When deceleration is required, the drive motor can convert part of the kinetic energy reduced by braking into electrical energy to charge the battery, thereby recovering the energy wasted during braking.

WEY brand's new compact SUV will be the first to be equipped with Lemon Hybrid DHT

In terms of the final experience, the Lemon Hybrid DHT brings users the feeling of "fast, smooth, quiet and economical". In all speed ranges and scenarios, it has the characteristics of fast power response, strong acceleration ability, smoothness, comfort, quietness and fuel efficiency. At the end of the live broadcast, Song Dong first gave a spoiler in advance that the first product equipped with the Lemon Hybrid DHT will be the new compact SUV that the WEY brand is about to launch, with a comprehensive fuel consumption of only 4.7L, which will soon meet everyone.

Under the general trend of energy conservation and emission reduction, when joint venture brands dominate the hybrid market, Great Wall Motors was able to break through the technical barriers of joint ventures, and completely independently designed and developed the Lemon Hybrid DHT with completely independent intellectual property rights, which was highly praised by the industry and the media, and promoted the development of China's hybrid technology. Soon, products equipped with Lemon Hybrid DHT will be launched on the market one after another, allowing more users to enjoy high-quality travel, making "fast, smooth, quiet and economical" a word-of-mouth reputation among users.

As a winner of Toutiao's Qingyun Plan and Baijiahao's Bai+ Plan, the 2019 Baidu Digital Author of the Year, the Baijiahao's Most Popular Author in the Technology Field, the 2019 Sogou Technology and Culture Author, and the 2021 Baijiahao Quarterly Influential Creator, he has won many awards, including the 2013 Sohu Best Industry Media Person, the 2015 China New Media Entrepreneurship Competition Beijing Third Place, the 2015 Guangmang Experience Award, the 2015 China New Media Entrepreneurship Competition Finals Third Place, and the 2018 Baidu Dynamic Annual Powerful Celebrity.