Batteries and battery management systems -Lithium - Ion Battery Equipment

Pay attention to safety issues of batteries and battery management systems -Lithium - Ion Battery Equipment

Since March, there have been 7 or 8 electric vehicle battery fire incidents in China, bringing the issues of battery safety and battery management system safety to the forefront. In these fire incidents, the temperature of the power lithium battery was uncontrollable and rose linearly after being heated, which led to combustion and explosion. This phenomenon has a professional term called thermal runaway of power lithium batteries.

The rise in battery temperature is the culprit of fire and combustion, and the reasons for the occurrence of heat are nothing more than the following four points: heat generated by side reactions in the battery, heat generated by overcharging, heat generated by electrical triggering short circuit, and heat generated by electrical triggering after collision. If the reason is found in production design, the main issue lies in battery design and battery management system.

In his speech, Mr. Ouyang Minggao, Executive Vice Chairman of the Council of 100 Electric Vehicles of my country, analyzed in detail the safety of vehicle power lithium batteries and their battery management systems, and gave on-site examples of multiple methods for thermal runaway assessment. Model, Cheyunji are organized into the table above.

He said that the problem of thermal runaway not only requires car companies to pay attention to battery selection, thermal design and protection design, and battery cell capacity, but also requires the battery management system to monitor the status of the electric vehicle battery pack at any time and monitor the remaining battery life of the vehicle. Make an estimate of electricity consumption, control the charge and discharge of the battery, optimize battery performance parameters, extend battery life, and fine-tune the monitoring unit to each battery.(Lithium - Ion Battery Equipment)

How hybrid products create economies of scale

Hybrid vehicles are seen as a phased product in the development from gasoline vehicles to all-electric vehicles. Perhaps because they have only a short-term advantage, they have not been widely popularized.

Lacking firm policy planning and guidance, hybrid vehicles have yet to achieve scale effects. New transmissions and hybrid powertrains have a small number of orders but not enough sales to support them. A major difficulty faced by parts suppliers is the effective allocation of vehicle model development and mold costs.

The solution to this problem is ultimately to return to technology - to develop standardized hybrid products. Niu Mingkui believes that products must meet three requirements in order to adapt to the scale of hybrid models on the market at this stage. First, it must be easily platformed, which facilitates transfer between models without the need to develop additional new products; second, it must have good compatibility and can be compatible with traditional engines and gearboxes; third, it must be able to provide hybrid products for the Chinese market. Customized technical parameters, for example, considering the cost sensitivity of our market, single-motor solutions should be developed as much as possible.

Promote the implementation of charging infrastructure and unify charging software and hardware standards

The relationship between electric vehicles and charging piles is like a chicken and an egg. When policies support and electric vehicle companies are eager to try, charging piles that have not yet caught up have become a bottleneck restricting development. On the one hand, the scale cannot meet the demand for charging at any time in terms of quantity and coverage. On the other hand, replenishing power when parking at night is a habit of many electric car owners. The implementation of private charging piles still faces the problem of increasing capacity. Such as power grid issues and management and other property issues.

At the forum, speakers put forward several business ideas regarding the promotion of private charging piles. The site advocates the use of a crowd-funding model to solve the problem of profitability, integrating resources from all parties, providing money and land; at the same time, it advocates a sharing economy way of thinking to allow private charging piles to enter the community; at the same time, the management level can also assist property companies in fulfilling their responsibilities Look for points of interest outside. Dongfeng Nissan Electric Vehicle Marketing Director Xu Xiaohui gave an example. In addition to clarifying the management responsibilities of charging piles, charging facilities and property networks can be interconnected to provide property management companies with reminders and warning functions for unpaid users.

In addition to commercial means, policies have also given some consideration to the placement of charging piles in residential buildings. Kadak also suggested that the Ministry of Housing and Urban-Rural Development introduce construction regulations for residential buildings and set the main line of the charging network as an indicator for advance planning. In this way, electric vehicle charging in every household will become a standard configuration, similar to natural gas, heating and Internet connections.

After the infrastructure is put in place, the charging interface is not suitable for various types of vehicles, and failure to charge occurs from time to time. To be implemented simultaneously with the increment, there is also the formulation of standards. At this point, both software and hardware aspects need to go hand in hand. The physical interfaces of charging piles and vehicle chargers must be unified, and the software charging protocol standards also need to be further refined.

The research scope of my country Automotive Technology Research Center's new energy research includes motor electronic control, charging and other vehicle-related testing, evaluation and standardization work, and is directly aligned with national standards. Dr. Wang Fang, chief expert of the New Energy Laboratory, introduced the testing and standardization work in "interconnection" and "charging safety". The interconnection content involved includes charging interfaces, DC fast charging communication protocols, and vehicle charger testing. Charging safety also covers the safety of the charging facilities themselves, the software safety of the charging facilities and vehicle protocols, vehicle components and Interface security and many other aspects.

Electric vehicle data collection and public operation management

The leasing model of time-sharing leasing in the Beijing, Shanghai and Guangzhou regions of my country has been applied on a large scale. Sharing models such as public leasing are a way to promote electric vehicles into individual homes. At the same time, the management platform for intelligently mobilizing electric vehicles can also obtain a large amount of data accumulation on electric vehicle performance and user usage habits.

On the public data collection platform, vehicle information acquisition and transmission generally follow the process of data collection-communication transmission-fault analysis. Taking Beijing's electric car rental management system as an example, the platform mainly collects battery technical status data, including detailed data such as voltage, temperature, and current of each battery. At the same time, the vehicle will also transmit back vehicle information including speed, gear, location information, etc. The predetermined push codes for common vehicle faults must also be sent back to the platform in real-time transmission mode.

Regarding the operation and management of public rental electric vehicles, the first thing to ensure is the safe completion of a complete set of driving rights handovers. In the case of time-sharing leasing in Beijing, the entire system for managing vehicle operation, return, and payment has been connected to the charging management system of electric vehicles. In the process of borrowing and returning a car, users have to go through the electronic code key retrieval and the charging system to stop charging. On the one hand, it ensures the safety of the rental vehicle, and on the other hand, it also opens up the connection to the charging system to achieve safe disconnection. electricity.


During the on-site roundtable session, one of the questions was: With the reduction of new energy policy subsidies and the cancellation of license restriction exemptions, will the development of electric vehicles hit a cliff? The site is relatively optimistic about the market environment after the policy change, and is more inclined to use "market filtering". As the craze caused by new energy returns to rational thinking, the increasingly mature automobile market will eliminate companies that fish in troubled waters, while retaining companies that research products in a down-to-earth manner. Moreover, at the forum, we can see that a batch of latest standards that are closely related to safety, large-scale, and suitable for home use are on the way. By then, the development of electric vehicles will impose more stringent specifications and constraints on quality details.



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