Volvo Cars takes on safety challenges surrounding electric cars

Volvo has theoretically identified all the electric-related safety scenarios in the stages before, during and after a collision. After careful study of these scenarios, the company's engineers will create solutions for handling each and every situation identified, guaranteeing that all future electric cars fully match Volvo's renowned safety standards in every respect.

"A holistic approach and results from real-life traffic conditions are always the starting-point for Volvo's safety work. Based on our massive database featuring input from actual road accidents, we know where the focus must lie in everyday traffic conditions."

"The solutions we have developed for our forthcoming electric cars therefore take into account the situations that are unique to this type of car," says Volvo Cars' safety expert, Thomas Broberg.

[B][U]Comprehensive testing under way[/B][/U]

Volvo's safety tests take place in several different stages. First at component level, then for whole systems and finally the complete car is safety-tested, both virtually on computers, and physically in Volvo's technically advanced crash-test centre.

Volvo is using its unique know-how from actual traffic conditions when carrying out detailed testing and verification. Furthermore, the company bases its entire test regime on the general requirements and protocols of the industry's safety institutes.

"We may well see further down the line that cars powered solely by electricity can be made even safer than cars with combustion engines. We like to see electrification technology as an exciting challenge - even from the safety viewpoint," says Thomas Broberg.

[B][U]Preparation for every phase of the accident sequence[/B][/U]

When Volvo analyses safety scenarios on the basis of actual traffic situations, the engineers use a model that illustrates the sequence of events in a real-life road accident. The whole process is divided into five phases: from the normal driving situation to after the accident has occurred. Based on these five phases, Volvo develops new safety solutions and improves existing ones.

This approach covers the entire sequence from giving the driver optimal preconditions for safe driving, for instance by providing excellent comfort and stability-enhancement functions, to systems that alert the driver or automatically step in to avoid a collision.

And if a collision is unavoidable, Volvo's cars offer highly-advanced impact protection as well as solutions that assist both the driver and the emergency rescue services after the accident has occurred.

[B][U]Unique solutions for electric cars[/B][/U]

All Volvo's existing safety systems will also be available in the company's electric cars. However, electric power also adds new possible safety scenarios to the overall picture and these too must be dealt with.

In the safety work that is currently being undertaken in the field of electrification, Volvo's safety experts have meticulously analysed the five accident sequence phases and developed unique solutions for the battery and for protection of the occupants as necessary.

1. [B]Normal driving[/B]: A comprehensive and advanced monitoring system keeps watch and ensures that each cell maintains the correct voltage level and optimal operating temperature by regulating the cooling system. This is of significance to both safety and battery capacity. In the event of any deviation, the battery is automatically shut down as a preventive measure.

2. [B]Conflict[/B]: The battery fitted to Volvo's plug-in hybrid weighs about 150 kg. This added weight creates new conditions for the vehicle's dynamics and alters the car's behaviour, for instance, in fast avoidance manoeuvres. Volvo's existing platforms and braking systems can handle the increased mass, and Volvo's DSTC (Dynamic Stability and Traction Control) helps the driver contain the situation.

3. [B]Avoidance[/B]: If a collision is imminent and the driver finds it difficult to handle the situation, the vehicle can activate automatic safety systems such as Collision Warning with Full Auto Brake and City Safety to avoid or reduce the effects of an impact. These systems can be used in cars with electric power just as they can in other types of car.

4. [B]Collision[/B]: In order to reduce the effects of a collision, the battery is well-protected in the rear of the car between the wheel housings, separated from the car's crumple zones.

5. [B]After the collision[/B]: The battery has a security cut-out that functions like a household earth fault circuit breaker. It shuts down and isolates the battery if the current travels in the wrong direction, for instance if two cables are pressed together as a result of an accident. Volvo also works in close cooperation with the emergency rescue services, providing them with detailed instructions on how best to handle various Volvo models in the event of an accident.

[B][U]Servicing safety[/B][/U]

The cars are equipped with a service cut-out to quickly and safely disconnect the car's power supply.

[B][U]Recycling and safety[/B][/U]

Volvo Cars and the battery manufacturers have far-reaching product responsibility with regard to both production and recycling. This ensures proper handling of the battery when it comes to the end of its life in the car.

[IMG]http://www.oneshift.com/showroom/uploadimages/resized-2009092404314267.jpg[/IMG]
[I]Plug-in hybrid crash test shows battery pack to be undamaged after a full-scale rear crash[/I]

[IMG]http://www.oneshift.com/showroom/uploadimages/resized-2009092404255505.jpg[/IMG]
[I]Plug-in hybrid rear crash test[/I]

Credits: JRC