Once upon a time, whenever traditional car companies released new energy vehicles, there would always be people on Weibo making fun of them with this statement.
But Changan seems to have something to say about this. “In the next 3-5 years, 80% of China’s fuel vehicle brands will be closed or transformed,” said Changan’s chairman, Zhu Huarong, at the China Electric Vehicle Hundred People’s Congress at the end of last month. Half a month later, Changan Automotive released a new pure electric brand, “Deep Blue,” at the 2022 Global Partner Conference; and a week later, the Changan Deep Blue Technology Sharing Conference came as scheduled.
At the conference, Changan released its all-electric digital electric drive platform EPA1 under its Deep Blue brand. CEO of Changan New Energy, Deng Chenghao, passionately referred to the EPA1 platform as “five years of hard work sharpening one sword.”
If it were a savvy businessman who said this, I would at most say, “Good acting”. But from the first sentence that Deng Chenghao spoke on stage, I smelled the same aura as mine – he must be an awkward and even somewhat introverted STEM person like me. And this unconventional sentiment expressed by such a STEM guy resonated with me greatly.
This resonance made me believe that Changan may have really put a lot of effort into this new platform, EPA1. Changan said that EPA1 is a highly efficient, high performance, intelligent, and safe digital platform, which was perhaps not just empty words.
Changan proposed an interesting new concept: powertrain electric efficiency. It refers to the ratio of useful output power of the electric drive system to the electric energy consumed by the power grid, reflecting the comprehensive electric efficiency of new energy vehicles. More intuitively, the higher this parameter value is, the more value users get for their money when charging their vehicle.
Regarding this new concept, Changan claims that the powertrain electric efficiency of the EPA1 platform is 78%, while the industry average is 70-75%. STEM people are always more sensitive to numbers. When I first saw this PPT, I wondered, what makes Changan declare that it can be 3-8 percentage points higher than the industry average?Longfor’s explanation is that this improvement is achieved by improving the efficiency of various subsystems, such as electric drive system efficiency, charging system efficiency, battery system efficiency, energy recovery system efficiency, and so on.
The response from Deng Chenghao, who is also a “science and engineering” type, is what really dispelled my “science and engineering” style question.
Deng Chenghao used specific numbers to explain this issue, taking the new generation electric drive system equipped on the EPA1 platform as an example.
Changan used 5 core technologies to improve the efficiency of the new electric drive system. Among them, the eight-core flat wire winding technology can improve it by 0.9%, the rotor double V topology structure increases it by 0.4%, the ultra-low resistance wire improves it by 0.1%, the adaptive control algorithm improves it by 1.2%, and the low resistance topology structure optimization improves it by 1.3%.
To be honest, I don’t really understand what these terms actually mean, but I can understand that these technologies can bring tiny improvements to the electric drive system.
“It is these tiny fractions of decimal point percentage, cumulatively adding up to 95% of the highest efficiency of the new electric drive system.”
As the saying goes, “to understand one thing, you must know ten.” Perhaps it is the accumulation of such details that ultimately allows the power system’s electrical efficiency of the EPA1 platform to reach 78%.
The Drift Dream of EPA1
Changan summarizes EPA1 platform as a power platform that is based on rear-wheel drive and supports both four-wheel drive and double-motor extension, and it is also the “first fully electric platform with multi-power configuration compatible with pure electric, extended-range, and hydrogen fuel cells.”
In terms of acceleration performance, taking the C385, the first model of the EPA1, as an example, it is equipped with a single motor with a maximum power of 190 kW at the rear axle, and its tested acceleration time is 5.9 seconds per hundred kilometers.
In terms of handling, the EPA1 platform is equipped with an H-arm multi-link independent suspension system. Regarding the structural details of this rear suspension, there was not much interpretation in this communication meeting. Changan claimed that this rear suspension can achieve better following performance, high-speed stability, riding comfort, and provide a more delicate driving experience. However, the true performance of this suspension still needs to be experienced by us when we get a chance to test the actual car, before making conclusions.The EPA1 platform is based on the H-arm multi-link suspension design, achieving a 50:50 front-to-rear weight ratio through a balanced weight distribution structure. The significance of this number is clear to those who value handling performance.
A 50:50 weight distribution ratio represents a perfectly balanced structure, providing superior dynamic balance performance. This is likely the most significant factor behind Changan’s confidence in featuring the C385 in their drifting promotion videos.
As for the chassis, what concerns me most is its braking performance. Deng Chenghao indicates that the EPA1 platform is equipped with the latest international double-redundant brake system, offering both comfortable and sporty braking styles.
Previously, the brake system on the Polestar 2 left a deep impression on me. The braking force could be gradually reduced when the vehicle was coming to a stop, effectively eliminating “jerking” caused by sudden deceleration in urban conditions and providing me with a much more pleasant ride experience.
I am curious to see if Changan’s claimed “comfortable” braking style can achieve similar results.
The era of domain control architecture
The EPA1 platform adopts the latest generation of domain control electronic and electrical architecture, which includes three major domains: vehicle control, cabin domain, and self-driving domain, with support for SOA service expansion.
The direct benefit of centralizing vehicle control functions is faster OTA upgrades.
This is easy to understand: previously, different functions were scattered across various controllers. When the vehicle received an OTA update package, it had to transmit the update file from the gateway to each subcontroller and then execute the update. By using domain controllers, this intermediate process is greatly reduced, resulting in faster OTA upgrade speed.
Changan mentions that the OTA time for the EPA1 platform is within three minutes.
Meanwhile, to ensure regular vehicle use during the OTA process, Changan has introduced a dual partition upgrade technology in the cabin domain. This concept is similar to the previous A/B partition seamless update feature on smartphones. For example, when the user is using partition A, and the vehicle receives an OTA update, the update will be executed on partition B, and normal use of partition A will not be affected during the update. After the update on partition B is completed, the user’s operation can be seamlessly switched to partition B.
One benefit of this approach is to provide a “no-sense OTA” user experience, and also to avoid vehicle breakdowns caused by failed upgrades.
In terms of vehicle control, Changan has introduced the smart whole-vehicle domain controller “Changan Smart Core”, which integrates 7 control modules, including VCU, gateway, Ethernet gateway, and T-BOX.
Changan Smart Core is also Changan’s first independently developed intelligent whole-vehicle domain controller with complete independent intellectual property rights. It contains more than 80 patents, integrated with over 1500 core devices, and achieved 100% remote diagnostic coverage. Its performance has been increased by 70% compared with traditional split controller, while its volume has been reduced by 70%.
In the cabin domain, the EPA1 platform selected the currently most powerful Qualcomm 8155 chip platform in the industry, achieving one machine to multiple screens.
In terms of self-driving, the EPA1 platform adopts a multi-chip redundant control design, which can collect data from all 27 perception components of the vehicle. Changan’s optional vehicle equipped with this self-driving system can achieve L4-level “driving and parking integration” intelligent driving.
The “Chip-Car-Cloud” is the three-pronged security of the new platform.
No matter how the car evolves, safety is always a hot topic that cars pursue as a basic tool for transportation. Changan has achieved high security attributes for the EPA1 platform through the “Chip-Car-Cloud” triple security architecture, according to Deng Chenghao.
Let’s talk about “chip” security first, which is actually battery safety.Changan has developed iBC, a digital battery manager, based on the EPA1 platform, which ensures battery safety in both active and passive aspects.
In terms of active safety, Changan ensures that the probability of thermal runaway of battery cells and packs is close to zero by optimizing the selection of battery cells and monitoring the manufacturing process with full monitoring and dual monitoring of vehicle cloud BMS. In terms of passive safety, Changan utilizes seven major technologies, including full insulation of the battery, alcohol cooling, and transient pressure relief, to effectively avoid the occurrence of the thermal runaway problem of the battery pack even in extreme circumstances.
In terms of “car” safety, based on the new pure electric drive platform architecture, Changan has designed a 5-horizontal-9-vertical-surround-type body with more than 45% high-strength steel, which meets the C-NCAP five-star safety standard and provides comprehensive surrounding safety protection for the battery.
In terms of “cloud” safety, data safety is ensured by Changan’s 5+1 information security and privacy protection measures, as well as privacy protection strategies covering the vehicle end, cloud end, and mobile end, which achieve the objective of protecting user information.
However, the specific performance of each vehicle model on the EPA1 platform is still the most important factor for consumers.
At this communication meeting, Changan also revealed some details about the C385 model, including its dimensions of 4820 mm in length, 1890 mm in width, and 1480 mm in height, with a wheelbase of 2900 mm and a drag coefficient of 0.23 Cd.The most exciting thing is that, in addition to the pure electric version, Changan has announced that the C385 also has extended-range and hydrogen fuel cell models. While the energy forms may differ, the power output of each model is the same, and Changan uses these specific examples to tell consumers what kind of platform can be called a fully digital electric platform.
Looking specifically at the range performance of the different models, the pure electric version can achieve a range of over 700 km under CLTC conditions, with energy consumption as low as 12.3 kWh/100 km; the extended-range model can achieve a comprehensive range of over 1200 km on a full tank and full battery, with an all-electric range of over 200 km and a fuel consumption rate of less than 4.5L/100km; and the hydrogen fuel cell version can also achieve a comprehensive range of over 700 km, with a hydrogen consumption rate of less than 0.65 kg/100 km, and can achieve a 3-minute superfast recharge.
In addition, the C385 is equipped with a 14.6-inch swivel display screen, electric lifting tailgate, frameless doors, and hidden door handles. As for more detailed information about the C385, Changan will undoubtedly prepare another separate press conference.
Thinking of this, I feel that Changan seems to have completely understood the game of the new forces – from the industry conference to the brand release, to the platform technology sharing conference, within a month, Changan has launched a set of intensive new energy combinations.
This intensive release feels a lot like the weekly new car information releases of a certain new brand. Compared to the new forces releasing only limited information on one model per week, Changan’s regular sharing from brand to platform clearly has more valuable content.
Even if Changan continues to release new models like the C385, including new technologies, at this pace, they will be even more innovative than the new forces.
In the future, who would dare to say “As long as traditional car companies make an effort…” I will definitely use Changan’s example to shut him up.
This article is a translation by ChatGPT of a Chinese report from 42HOW. If you have any questions about it, please email bd@42how.com.