In the case of rising the new energy auto industry, accompanied by the surge in new energy vehicles, reports on various new energy vehicles have gradually entered the public vision. Safety issues for new energy vehicles have become a social hot problem concern for all parties. According to incomplete statistics, since 2010, there have been 49 cases in my country’s new energy vehicle safety accidents, analyzing these 49 cases of accidents, charging, battery failures, collision, and water-related are important incentives that cause safety accidents, and accidents caused by battery failures More than 50% of total.
The cause of causing battery failures is a variety of diversification, but important performance leads to energy concentrated release of dynamic lithium batteries under thermal abuse, electro-abuse and mechanical abuse, including the release of electrical energy and the release of chemical energy. Finally, it focuses on thermal out-of-control expansion of dynamic lithium batteries, which leads to the burning and explosion of vehicles..
In order to improve the performance of the vehicle, each business car company is trying to add a more powerful power lithium battery on their new energy models.. The new energy automotive industry seems to have raised a high-rate energy battery technology.
The higher the power lithium battery is higher, which means that the harm caused after the accident, the larger, and the ride is facing higher security risks.. A high-proportioned energy battery of 350WH / kg at 350WH / kg, which releases the temperature when the heat is out of control, can be up to 1200 ¡ã C.
In the vehicle battery pack, there is often a hundred thousand batches, once a safety accident occurs, the consequence is unimaginable.. At the same time, in addition to the burning, explosion, passengers in the explosion, passengers will also face electrical energy release and chemical leakage problems.
. The safety technology of new energy vehicles face severe challenges. Engineers are trying to improve the safety performance of new energy vehicles to reduce the probability of vehicle accidents, reducing the damage of the car personnel during the accident, and raise the probability of ride a rescue after the accident.
. In addition to optimizing the structural design of the vehicle, upgrade the vehicle body material, improve the safety system of the vehicle, the engineers also focus on the power lithium battery system of new energy vehicles. New energy vehicle power lithium battery system is important by the battery, the power of the power, the safety of the power, lithium battery system, relies on safe and high-quality battery, advanced BMS technology, perfect thermal management system, mature Configuration technology, protective system design and protection circuit, etc.
. The important functions of BMS are safety monitoring and management of the power lithium battery system of new energy vehicles..
The BMS system mounted by the vehicle is also slightly different from the influence of the new energy vehicle.. However, BMS’s basic features include: battery parameter detection (SOC, SOH, SOE), fault diagnosis, security control, and alarm, equalization control, temperature control, function security, EMC, etc.
. BMS safety management, especially for thermal lithium battery systems, the prevention and treatment of thermal lithium battery system, is especially important for the improvement of new energy vehicle safety performance..
BMS should prevention and exclude in the design of thermal out-of control.. In the overall design, consider the electric or abuse (overshoot, overprint, electrical short circuit, etc.
), thermal abuse (thermal accumulation, temperature component out of control, etc.), mechanical abuse (collision, tip, puncture, fall, etc.).
BMS can be divided into two aspects of thermal out-of-control and thermal out-of control and thermal out-control expansion of the vehicle’s battery system.. In the initial heat failure phase, BMS collects the working state of the battery, temperature, etc.
. When the thermal out of control occurs, the BMS locks the electrical cell in an abnormal state and alert to the ride personnel..
By judging the abnormality of the battery, BMS can use equalization, cooling, heating, isolation and other means to suppress heat out of control, prevent thermal out-of-control expansion.. After the vehicle’s power lithium battery system enters the thermal out-of control expansion, the BMS adjusts the power lithium battery ventilation system while issuing a warning, increases water cooling, opening fire extinguishing measures, partially or overall the battery, and cut off power lithium Battery system power supply, inhibiting thermal out-of control expansion.
BMS technology has been greatly improved in recent years, many aspects have entered the actual application stage, but some parts are still not perfect, and BMS is not very mature than three electric technology, with great improvement space. In terms of data collection, such as SOC (battery remaining capacity) parameters have a lot of progress space in estimation accuracy of power lithium battery discharge adjustment, battery safety, service life, and a direct impact on charging machine CAN communications, etc..
In terms of thermal management components, advanced BMS can be adjusted within ¡À 2 ¡ã C, while most of the BMS system adjustment errors can be made in the future.. In addition to the issues on the BMS, BMS exposes some problems in applications.
. Typical examples are the coordination of BMS and vehicle electronic control systems, this is a big question, a small problem..
We understand that BMS takes safety emergency measures based on the working state of the power lithium battery system.. However, during the actual use of new energy vehicles, BMS should collect more parameters to make the correct decision.
. When new energy vehicles travel in still charge or low speed, the dynamic lithium battery system has a thermal out-of-control expansion, and BMS performs power-down processing is the correct judgment..
However, there is a similar condition in the high-speed driving of the highway, and the BMS is powered by power-down processing.. This is also a typical problem that the BMS system of the vehicle is not coordinated with the electrical system of the whole vehicle.
. BMS conducts alarm after detecting heat loss, prompting the driver. Will the driver adopted? Whether the driver will be scared because of the BMS alarm, brewing more serious problems? Especially new energy passenger cars, passengers will not cause crowding and stepping accidents due to escape, causing unnecessary casualties due to escape.
Whether the electrical system of the vehicle can make a symptom, such as the double flash of the vehicle, assist the speed of the vehicle? If the data of the external sensor can be imported into the BMS, it may make BMS more accurate judgment, then these issues may be able to solve. Experts scholars in China have begun research and exploration for BMS and vehicle coordination, but they want to solve this problem, but also facing a big difficulties..
Although the car enterprises and BMS companies may be aware of the safety hazards, but due to lack of relevant policy specifications, the current BMS and vehicle electrical associations are still in a state of being ambiguous.. About the vehicle enterprises, this may mean that the huge production costs will be paid, and the BMS is concerned, and there may be leakage of the core technology in the process of opening the interface to the car, thereby losing the market competitive advantage.
. The flourishing of the new energy automobile industry, the security attribute of the product is the cornerstone, and there will be no more brilliant industries with this cornerstone..
Future New Energy Cars will face more serious challenges, I don’t kill Belley, Berren die. In addition to the promotion of our own technologies, the whole car and BMS have improved new energy vehicles as an organic whole consider the connection and synergistic issues between various components, and the use of users’ lives and property. In the first position, only this, the new energy automotive industry can achieve leaping on a solid foundati.