some security solution of the Power battery

Below is the essence of a conference. Discussion is put forward Ten major safety problems of Power battery : 1. The batteries safe 2. 3 group security. The battery Design safety management, 4. 5. Rechargeable security 6. 7. Use safety security early warning 8. Daily maintenance 9. Safety protection 10. Security hierarchy. This sorting manuscripts are selected from 10 questions focus on three core issues, and put forward the solution of this group, specific as follows:

1. The batteries safe solution

Group C: batteries, battery module standardization

Through standardization can improve several aspects:

(1) design, the design of the batteries problem focused exposure, focus on;

(2) the production equipment, will have a high level of standardization of some equipment, equipment enterprise product iteration will be faster;

(3) to promote continuous improvement and experience, through the standardization, can put the excellent equipment to promote the experience of the cell to cell and components industry, it improved the level of safety technology of battery industry as a whole.

Group D: the standardization of batteries

The standardization of batteries can reduce low level repeated labor. Batteries standardized itself has a lot to improve performance, the safety of the batteries more manufacturers to do the same standard batteries, batteries cost will decline, security will increase. From the point of urgency and realizability, it is urgent and relatively easy to implement.

2. The solution of group security

Group D: the battery thermal management design safety is very important

Group security, good thermal management design, heat balance, the BMS is small current balance, but can put the different battery voltage difference caused by the difference in temperature before equilibrium, the temperature of the can, because the battery is electrochemical equation, the anode is positive correlation, the cathode is negative correlation, voltage difference is the anode during the very word is bigger, so the temperature is a big influence on its voltage.

One aspect of the welding process, of course, it is also important, is not the same as the welding process can lead to internal resistance is not balanced rise, so from the several dimensions to improve its safety in groups.

Group F: PACK electricity, thermal management

Security issues will ultimately comes down to the battery module, using the method of system theory to the safety of batteries and PACK, BMS for each batteries do precise detection, control and early warning.

At the same time also can't because only consider the battery safety, and ignore its life, we should not only guarantee the safety of the battery, also should as far as possible improve the battery life. If there is no good life, lose the use of the lithium battery.

3. The battery management solution

Group C: BMS security policy

The battery system classification and formulate the corresponding security goals, according to the target set measurement, recognition, processing of security policy and validated. If the industry focus on this aspect of the work, to improve the level of battery safety in a short time.

Group F: BMS of batteries detection, control and early warning

We should believe fundamentally Lithium electricityPool itself is not safe, it is guilty inference, it itself is not safe energy device, need on the basis of BMS control, heating control, fire extinguishing mechanism and device in time outside, find the fire, like a, immediately start extinguishing fire extinguishing device.

4. Design security solution

Group F: scientific and reasonable system design, production process control

All kinds of battery materials, battery structure all have advantages and disadvantages, just different from the degree of impact on the security, as long as the design science, manufacturing precision, to a certain extent can create security acceptable power battery.

5. Rechargeable security solution

Group A: add the battery fast medical function charging equipment

Vehicle charging 80% 90% complete when do large current detection, through the change of dc memory to find inconsistencies in the battery pack, achieve the goal of fast battery check-up.

PACK before they go out, will be a large current pulse charging and discharging, and at the end of the charge to do a large current pulse charging, make a big at the end of the discharge current pulse discharge, through this method, the battery combination of inconsistencies, may be the problem of batteries, might have some connection problems, may also be a cable has a problem, the large current pulse will clearly show some abnormalities.

The application of this method to the client, because the client in addition to charging pile no detectable.

Group D: early charging the battery test current pulse

To the SOE, SOH of different battery charging current, at the beginning of the charging for current pulse detection, found inconsistencies, issued a security alert in advance. Because at the beginning of the charging, the battery PACK is under normal temperature, the end of the charging when the temperature of the battery PACK may be increased by 10 ° or 15 °, causes the battery voltage imbalance, so at the time of equilibrium test its inconsistency possible error smaller.

Real-time diagnosis, detection, in addition, the BMS on the car, charging pile, grid this tripartite coordination, sufficient to ensure the safety of charging.

6. Use the security solution

Group E: monomer thermal runaway in the state of how to ensure the safety of personnel

(1) delay thermal runaway aspects, there are some mature design method:

With fireproof materials, fireproof and heat insulation on fire prevention structure processing, such as Tesla's design as you can see, indeed, to some extent can delay the process of thermal runaway, delay to the whole process of thermal runaway monomer thermal runaway.

(2) increase the personnel evacuation time, take the initiative to do some testing:

Smoke detection test, chemical composition, heat, etc., through the detection early monomer thermal runaway, and to alert the driver and passengers, remind people to escape.

(3) limit processing:

Can't keep the driver in accordance with the conventional power to use, through the limit of power pattern, let the car has a certain power, but power is very weak, can do processing to pull over.

(4) to increase fire extinguishing equipment:

National standard at present electric buses are pushing to increase fire extinguishing installation, increase the extinguishing equipment may have advantages and disadvantages, because now the design of the battery box will increase the valve, if the injection of gas or gas gel, it can lead to internal pressure, may the explosion-proof valve to break through, will bring another problem.

If error monomer thermal runaway, gush out of these things, may cause the whole battery scrap, if sprayed out of gas, liquid or gel material will be a better choice to battery, no harm, hope to have this kind of material can achieve the effect.

(5) vehicle design.

In vehicle design to increase the safe escape device, electric cars, unlike traditional car, battery as the electric power source, only in the case of thermal runaway if by cutting off the power outage, the door is likely to be won't open, so if can increase can be quickly on the vehicle design, convenient to open the doors, or other device is also a viable option to escape.

7. The solution of the security warning

Group D: BMS monitor, VCU response, big data analysis

The car VCU do response to the problems. When car security problems, can let the driver to pull over, or do some corresponding action, and the VCU BMS collected information uploaded to the cloud, big data analysis VCU has a smart learning process, improve the reliability of safety early warning.

8. Daily maintenance solution

Group B: to make daily maintenance process and related laws and regulations of the country is very urgent and necessary

Now vehicles a lot of problems are out in the absence of routine maintenance or in the absence of mandatory testing standard. Traditional car have mandatory testing, electric vehicles as a new thing, related to the safety, reliability, had not reached the level of traditional car, what every 3 months, 6 months, or 1 year testing, which projects should be testing (system sealing, electrical reliability, reliability and so on all need to detect), this is the lack of related standards.

Now are the selling points of OEMS more electric cars need not maintain, but really this is completely run counter to the safety consciousness, therefore, countries should set mandatory                   testing standards, car should have mandatory testing requirement for the project.

In terms of feasibility or industry, formulate relevant national standards, OEMS for detection and maintenance projects or manual, easy to carry out.

9. Security protection solution

Group E: overcharge, overheating, connection security issues

(1) the overcharge the solution of the problem

Through the BMS, charger, VCU protection, the simplest is protected by BMS, if BMS doesn't work can also through the charger to protect, can also through the vehicle VCU to step in. Tackle the issue of overcharge, from a technical words is relatively easy to solve, and the effect is more obvious.

(2) the overheating problem

In the process of charging, due to the large batteries of overheating or connection impedance caused by overheating will cause thermal runaway. About overheating to solve the problems mainly from two aspects, one is reduce the density of batteries, reduce the connection impedance, this went up from nature to reduce risk; The second is to strengthen heat dissipation, we hope that in the charging process can take more effective cooling measures, such as by strengthening air-cooled or liquid-cooled measures, can reduce the possibility of thermal runaway in the process of charging, and the problem of temperature sampling, temperature sampling accuracy, how to effectively and reliably sampling temperature point, it may be thermal simulation and actual test results with all of us have a match.

(3) the solution of the connection failure

An accident happened recently in Shanghai and fly line connection charge on fire, and in charge of the fire accident, underground garage are relationship with the charging connection is very big. Connect battery gun plug, as well as ordinary car charger plug, if use for a long time, if the connection is not reliable overheating on fire. Currently in charging gb already has asked, charge in gun temperature sensor, more will be to collect charge gun in the process of charging temperature.

And charging gun and the service life of plug socket passes through strict calculation and verification, and to be able to meet the requirements of the service life of the vehicle. Daily inspection and maintenance, to figure out whether out plug socket contact has been reduced to a number, if has fallen below the safe value, then must be replaced, by the several ways of solving the problem of the charging connection.

10. Security level of solution

Group C: industry chain cooperation, OEMS and auto parts enterprises to establish specialized division of labor and collaboration system

According to the requirements of the automotive industry, from the APQP, PPAP according to the requirements of the automotive industry, division of labor, responsibilities clear, realize the product whole life cycle can be monitored, traceability, from the aspects of cooperation mode change to improve the safety level of power battery.

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