Battery 10 Security Problems and Solutions
Network News Channel Set yin battery: The following is the essence of a meeting is proposed to explore Ten battery safety issues: 1. Safety cell group 2. 3. Battery Management 4. Security 5. Charge Engineered Safety Safety Safety 6. 7 safety warning 8. routine maintenance 9. security 10. The security classification. This finishing manuscripts were selected from 10 issues in the three core issues were the focus of discussion, and propose solutions to the idea of this group, as follows: 1, batteries security solution ideas Group C: batteries, battery standardization through standardization module can improve several aspects: (1) design, the design of batteries concentrated exposure, focus; (2) production equipment aspect, the device will be a corresponding degree of standardization of higher equipment enterprise product iterations will faster; (3) promotion of continuous improvement and experience, through standardization, can be excellent ancillary equipment and spare parts suppliers supporting business experience to promote the industry, so the overall level of technology to improve the safety of the battery industry. Group D: Standardization Standardization cell batteries may reduce the repeated low-level work. Batteries standardization itself on the safety performance of batteries greatly improved, more manufacturers to do the same standard batteries, the batteries will decrease costs, increase security. From the urgency and realizability of view, it is more urgent is relatively easy to achieve. 2, group security solution ideas Group D: thermal management design is very important for battery safety group security, good thermal management, thermal equilibrium, BMS although a small current balancing, but can the voltage difference between the temperature difference caused by different cell balancing before them, because the temperature inside the battery is an electrochemical Nernst equation, the positive is a positive correlation, negative correlation is negative, the voltage difference is very positive burden is greater, then, the temperature of its voltage impact is significant. Of course, the welding process is a very important aspect, not the same welding process will lead to increased internal resistance is not balanced, so from several dimensions as a group to improve its safety. Group F: PACK of power management, thermal management security issue ultimately boils down to a battery module, the use of systems theory approach to safety on the batteries and PACK is, BMS to do accurate detection of each of the batteries, control and early warning . But also can not because only consider battery safety issues, while ignoring its life, IThey are necessary to ensure the safety of the battery, but also enhance battery life as much as possible. If there is no good life, to lose the reason to use lithium batteries. 3, the battery management Solutions Group C: BMS cell system security policy and to develop appropriate hierarchical security goals, developing measure, identify, according to the target security policy processing and verification. If the industry is to focus on doing work in this area, can improve battery safety levels in the short term. Group F: BMS batteries for detection, management and control, early warning should we believe fundamentally lithium battery itself is unsafe, it were guilty of inference, which itself is unsafe energy devices, it is necessary on the basis of BMS control on the outside heating control, and timely mechanism for fire extinguishing apparatus, such as a found in fire, fire extinguishing device starts immediately. 4, design security solution ideas F Group: system design scientific, rational, production process control of various cell materials, cell structure has advantages and disadvantages, but to varying degrees of impact on the security of it, as long as the design science , precision manufacturing, to a certain extent, can produce power battery safety acceptable. 5, charging safety Solutions Group A: quick increase in the battery charging device physical functions of the vehicle when the charging completion current detecting bigger 80% -90%, to find inconsistencies in the battery pack by the change in the DC memory place, the purpose of fast battery examination. PACK at the factory will be the pulse charging a large current and discharge, at the end of the charge made pulse charge a large current, at the end of the discharge do pulse discharge a large current, through this method, the inconsistent cell combination find out where the problem may be batteries, may be connected to the problem, it could be a problem with the data line, these large current pulse will show some obvious exceptions. The application of this method to the client, because the client in addition to the charging post outer no detectable means. Group D: initial charging of the battery a current pulse detection current SOE for different batteries, the charging of the SOH, its initial charging current detection pulse, inconsistency found, issuing a security alert in advance. Because the initial charging, the battery is PACK room temperature, the temperature of the battery when the charging end PACK may have risen 10 ° or 15 °, the electrical leadsVoltage imbalance the pool, so that inconsistency detection errors less likely when equilibrium. In addition, BMS real-time diagnosis, detection of vehicle charging poles, grid coordinate these parties to fully protect the security charge. 6, using the secure Solutions E: in a single thermal runaway how the safety of personnel (1) delaying thermal runaway aspect, some sophisticated design methods: fire-resistant material, the fireproof structure fire-proof insulation process, as can be seen in the design of Tesla, indeed to some extent, can delay the process thermal runaway, thermal runaway monomer delay to process the entire set of thermal runaway. (2) increased staff time to escape terms, do active detection: detection, detection, chemical detection of components of hot smoke, and the like, early discovery by detecting monomer thermal runaway, and to alert the driver and passengers, to alert people to escape. (3) limit treatment to do: You can not allow the driver to use in accordance with conventional power by limiting power mode, so that the car has some power, but power is weak, you can pull over for processing. (4) increasing the fire-fighting equipment: the current national standard electric buses are driving increased fire-fighting equipment, fire-fighting equipment may increase the advantages and disadvantages, because the battery box design will increase the explosion-proof valve, if a large number of injection gas or airgel out, it will lead to internal pressure, the explosion-proof valve may break, will bring another problem. If the thermal runaway monomer erroneous detection, to discharge these things, may lead to scrap the entire cell, if discharged to a gas, liquid or semi-gel substance without harm to the battery would be better to select, desirable to have this material to achieve this effect. (5) vehicle design: the design of the vehicle to increase the safe escape, electric vehicles and conventional vehicles are not the same, a battery as a sole power source of electric vehicles, in the case of thermal runaway event of a power cut off the power by means of a door there may not open, so if we can increase quickly, escape doors or other convenient means of escape open is also a viable option in vehicle design. 7, Solutions security warning Group D: BMS monitoring, VCU response, big data analytics car VCU made in response to emerging issues. Car in the event of safety problems, allowing the driver to pull over, or do some action, andThe VCU collected information is uploaded to the cloud BMS large data analysis, VCU has a smart learning process, improve the reliability of the safety warning. 8, Solutions routine maintenance Group B: developing processes and related legal provisions of the country daily maintenance is very urgent and necessary vehicles are now a lot of problems out in the absence of routine maintenance standards or no national mandatory testing standards. Traditional cars have mandatory testing of electric vehicles as a new thing, related to the security, reliability has not yet reached the level of a conventional car, what every three months, six months, or one year for testing, which items should be tested ( the sealing system, the reliability of electrical connection reliability and so be detected), which are related to the lack of standards. OEMs are now selling more electric cars do not maintain, but in fact it is entirely contrary to the sense of security, therefore, should develop national standards mandatory testing, OEMs should also have projects require mandatory testing. From the terms of feasibility, development of relevant national or industry standards, OEMs develop testing and maintenance of the project or manual execution is easier. 9. Solutions secured E Group: overcharging, overheating, connected to safety problems (1) to solve the overcharge problem through the BMS, charger, the VCU protection, the simplest is protected by the BMS, If the BMS does not work can also be protected by the charger, the vehicle can also intervene by VCU. About overcharge problem, solve it come from technology is relatively easy to solve, and the effect is more obvious. (2) solve the problem of overheating during the charging process, the core body due to overheating of the electric connection resistance due to excessive overheating can cause thermal runaway. On the overheat issue mainly from two aspects to address, first, to reduce the density of the batteries, reducing the connection resistance, which go up to reduce the risk from nature; the second is to enhance heat dissipation, we hope to take in the charging process more efficient the cooling measures, for example by strengthening measures air or liquid cooling, you can reduce the possibility of thermal runaway during charging, there is the problem of sampling temperature, the temperature of samples to be accurate, how effectively and reliably the temperature of the sample points, which may keep our thermal simulation and actual test results make it match. Solution (3) a connection failure earlier in Shanghai accident occurred, fire fly line connecting the charging, as well as undergroundGarage fire accident charge, in fact, relationships are with the charging connector is very large. Charging plug connector plug charging gun, as well as ordinary car charger, if long-term use, if the connection is not reliable will overheat and catch fire. Currently in charge GB have already demanded, on the gun charge will increase the temperature sensor, to capture the process of charging the charging gun temperature. There charging gun and plug socket life go through rigorous calculation and verification, to be able to meet the requirements of the service life of the vehicle. Routine inspection and maintenance, can be judged plug socket contact is not already reduced to a figure below, if the value has fallen below the safe, then it must be replaced, charging connector solve the problem through this in several ways. 10, the security level Solutions division Group C: chain collaboration, OEMs and parts enterprises to establish specialization and cooperation system in accordance with the requirements of the automotive industry, from APQP, PPAP the automotive industry and other sectors in accordance with implementation requirements, division of labor, clear responsibilities, to achieve product life cycle can be monitored, can be traced back to change the terms of the mode of cooperation to improve the security level of battery power.