On September 23, the "2015 National Forum on Electric Vehicle Technology Innovation" (EVTIF), hosted by the my country Automotive Technology Research Center and organized by Beijing Cardak, was held in Beijing. At this forum, experts from domestic and international automakers, parts suppliers, and relevant government departments from China and Germany shared their insights on electric vehicles.
After enjoying a half-day test drive on the electric vehicle track and a full day and a half of forum learning, we summarized the content and found that battery & battery management system safety, infrastructure construction, public operation management and other aspects were frequently mentioned topics at the conference. Here is a brief review of the conference.
Pay attention to the safety issues of batteries and battery management systems
Since March, seven or eight electric vehicle battery fires have occurred in China, bringing battery safety and battery management system safety to the forefront of public attention. In these incidents, the lithium-ion batteries experienced uncontrollable temperature increases after being heated, leading to combustion and explosion. This phenomenon has a technical term: thermal runaway of lithium-ion batteries.
Overheating of the battery is the main culprit for fires, and the causes of this heat are generally one of four: exothermic reactions within the battery, overcharging, electrical short circuits, and electrical impacts. If we look for the cause in the manufacturing process, the key lies in the battery design and battery management system.
In his speech, Mr. Ouyang Minggao, Executive Vice Chairman of the my country Electric Vehicle 100 Forum, provided a detailed analysis of the safety of automotive power lithium batteries and their battery management systems. He also presented several models used for thermal runaway assessment, which are summarized in the table above.
He stated that thermal runaway issues not only require automakers to pay attention to battery selection, thermal design, protection design, and battery cell capacity, but also require battery management systems to monitor the status of electric vehicle battery packs at all times, estimate the remaining battery power, control battery charging and discharging, optimize battery performance parameters, improve battery lifespan, and monitor the details down to each individual battery cell.
How to achieve economies of scale for hybrid products
Hybrid vehicles are considered a phased product in the transition from gasoline vehicles to fully electric vehicles, perhaps because their advantages are only temporary and they have not been widely adopted. According to data provided by Niu Mingkui, Senior Director of R&D at Schaeffler Automotive, in 2010, compared to the hundreds of thousands of hybrid vehicles produced on a single platform in the European, American, and Japanese markets, the number of hybrid vehicles in the Chinese market only reached tens of thousands.
Lacking a firm policy plan and guidance, hybrid vehicles have yet to achieve economies of scale. New transmissions and hybrid powertrains have received a small number of orders, but lack sufficient sales volume to support them. A major challenge for parts suppliers is the effective amortization of vehicle development and mold costs.
The solution to this problem ultimately lies in technology—developing standardized hybrid products. Niu Mingkui believes that products must meet three requirements to keep pace with the current scale of hybrid vehicles on the market. First, they must be easily platform-based, facilitating transfer between models without requiring the development of new products. Second, they must have good compatibility, being compatible with traditional engines and transmissions. Third, they must be able to customize technical parameters for hybrid products in the Chinese market; for example, considering the cost sensitivity of the Chinese market, single-motor solutions should be developed as much as possible.
Promote the implementation of charging infrastructure and unify charging hardware and software standards.
The relationship between electric vehicles and charging stations is similar to that of the chicken and the egg. While policies provide support and electric vehicle companies are eager to enter the market, the lack of charging stations has become a bottleneck restricting development. On the one hand, in terms of quantity and coverage, the scale cannot yet meet the demand for charging at any time. On the other hand, many electric vehicle owners have a habit of charging their vehicles while parking at night, but the implementation of private charging stations still faces grid issues such as capacity expansion and property management issues such as management.
At the forum, speakers proposed several business ideas for promoting private charging stations. They advocated using a crowdsourcing model to address profitability, integrating resources from all parties—those with money contribute capital, and those with land contribute land. They also promoted a sharing economy mindset to bring private charging stations into communities. Furthermore, from a management perspective, they suggested assisting property management companies in finding profit opportunities beyond their responsibilities. Xu Xiaohui, Marketing Director of Dongfeng Nissan Electric Vehicles, cited an example: in addition to clarifying the management responsibilities of charging stations, interconnecting charging facilities with property management networks could provide property management companies with reminders and warnings for users who have not paid their fees.
Beyond commercial approaches, policymakers have also considered the installation of charging stations in residential buildings. Kadak has even suggested that the Ministry of Housing and Urban-Rural Development issue construction standards for residential buildings, setting the main charging network as a pre-planned indicator. In this way, electric vehicle charging for every household would become as standard as access to natural gas, heating, and internet.
After the infrastructure is implemented, charging interfaces are often incompatible with various vehicle models, resulting in frequent instances of charging failures. Alongside the rapid expansion, standardization is also crucial, requiring simultaneous progress in both hardware and software. The physical interfaces of charging piles and on-board chargers need to be standardized, and the charging protocol standards on the software side urgently need further refinement.
The research scope of the New Energy Institute of my country's Automotive Technology Research Center covers all vehicle-related testing, evaluation, and standardization work, including motors, electronic controls, and charging, and directly aligns with national standards. Dr. Wang Fang, Chief Expert of the New Energy Laboratory, introduced the testing and standardization work in two aspects: "interoperability" and "charging safety." Interoperability includes testing of charging interfaces, DC fast charging communication protocols, and on-board chargers, while charging safety covers many aspects such as the safety of the charging infrastructure itself, the software security of the charging infrastructure and vehicle protocols, and the safety of vehicle components and interfaces.
Electric vehicle data collection and public operation management
In major Chinese cities like Beijing, Shanghai, and Guangzhou, time-sharing rental models have been widely adopted. Public rental and other sharing models are a way to promote electric vehicles in private homes. Simultaneously, intelligent management platforms for electric vehicles can accumulate a wealth of data on vehicle performance and user habits.
On public data collection platforms, vehicle information acquisition and transmission generally follow a process of data collection, communication transmission, and fault analysis. Taking Beijing's electric vehicle rental management system as an example, the platform primarily collects technical status data of the batteries, including detailed data such as voltage, temperature, and current for each battery. Simultaneously, the vehicle also transmits vehicle information including speed, gear position, and location. Pre-defined push codes for common vehicle faults are also transmitted back to the platform in real-time.
Regarding the operation and management of public rental electric vehicles, the first priority is to ensure a safe and complete handover of driving rights. In the case of time-sharing rental in Beijing, the entire system managing vehicle operation, return, and payment has been integrated with the electric vehicle's charging management system. During the borrowing and returning process, users must undergo an electronic key retrieval and a confirmation that the charging system has stopped charging. This ensures the safety of the rented vehicle and also establishes a connection with the charging system for safe power disconnection.
summary
During the roundtable discussion, one question was: With the reduction of subsidies for new energy vehicles and the removal of license plate exemptions, will the development of electric vehicles face a precipitous halt? The participants were generally optimistic about the market environment after the policy changes, leaning more towards a "market filtering" approach. As the initial enthusiasm for new energy vehicles returns to rational thinking, the increasingly mature automotive market will weed out companies that are merely trying to profit, retaining those that focus on solid product development. Furthermore, the forum showcased a batch of new standards focused on safety, large-scale production, and suitability for family use, which will impose stricter regulations and constraints on the quality details of electric vehicles.
