ARaymond Mobility Leaps Into EV Battery Module Connectivity With SimScale

ARaymond Mobility designs smart solutions that improve ergonomics and serviceability, save space, and allow for late customization on the automotive assembly line. Whether for passenger cars or commercial vehicles, ARaymond has the solution for the assembly and integration challenges. The world is changing. Trends like e-mobility, autonomous vehicles, and car sharing are reshaping the global automotive industry. ARaymond brings more than a century of experience to today’s complex assembly and integration challenges. ARaymond partners with the customers from the very first stages of the design process to come up with value-creating assembly solutions.

In the realm of electric vehicles (EVs), the challenge of efficiently connecting battery modules is a pressing concern. At the heart of this evolution is the expertise at ARaymond Mobility. Spearheading this transformation at ARaymond is Vincent Lin, High Voltage Electrical Interconnect Engineer at ARaymond and an expert with a history of developing high-speed and high-power connectors for high-voltage applications.

Vincent has previously worked at many well-known connector companies, where he innovated the DisplayPort connector to become the industry standard. His specialty, however, also lies in high-power electrical interconnect for EV battery modules. Lin’s mission with ARaymond resonates with the company’s long-standing reputation: leading the automotive fastening and assembly domain, emphasizing ergonomic, secure, and durable assembly processes. As the age of electrification dawns, ARaymond’s collaboration with automotive giants ensures simplified EV system architectures that are robust and designed using the latest engineering simulation tools.

Improving a Classic

Traditionally, solid bus bars were used for connecting and integrating EV battery pack modules, particularly for module-to-module connections. These copper bus bars, although standard, have several challenges:

• They have relatively expensive manufacturing and assembly
• Lengthy assembly lines due to the need for bolting
• Substantial investments in automated bolting assemblies
• Issues of vibration, thermal expansion, and consequently, unreliable contact resistance between modules
• The looming risk of loose bolts which could cause catastrophic short circuits in the battery
• Intolerance to z-direction misalignment and movement – imagine a car driving and this becomes apparent

Moreover, these module-to-module bolted busbars required additional components, such as spring washers, to counteract the issues stemming from vibration and thermal expansion, further adding to cost and supply chain requirements.

A New Type of Module-to-Module Connector for Electric Vehicle Batteries

Vincent and his team discovered SimScale, a cloud-native engineering simulation platform for engineers. The software, equipped with CFD, FEA, and harmonic analysis, was a revelation to the team because of its ease of use, cloud-native access, and team collaboration features.

ARaymond developed a revolutionary product to address the challenges described above of traditional connectors in electric vehicle batteries. The new flexible module-to-module connector is a quick and reliable solution for electrical interconnection between modules and busbars for EV/battery packs and has the following advantages:

• Robustness against vibration or thermal expansion
• Tool-free quick mounting connections
• Design flexibility, ensuring compatibility with various current/voltage ratings
• Options for manual or automated assembly
• Huge cost savings against conventional counterparts

Notable specs include a contact resistance of 80 micro-ohms from end to end, a voltage rating above 800V, and a current rating of 400 amps under natural convection conditions — all engineered to be resilient even under extreme vibrations. The product has operating temperatures of between -40℃ and 125℃ and passes the extreme vibration compliance test to USCAR-2-V4 class Performance Specification for Automotive Electrical Connector Systems. This standard has procedures included within its specification that are intended to cover performance testing at all phases of development, production, and field analysis of electrical terminals, connectors, and components that constitute the electrical connection systems in road vehicle applications.

Vincent used SimScale from the earliest stages of design. They used a CATIA CAD model imported as an STP file that is easily imported into SimScale. An oft-quoted standout feature by Vincent has been SimScale’s CAD associativity. With each CAD revision and its subsequent import into SimScale, the platform remembered the prior simulation parameters, boundary conditions, and geometry contacts/parts, effectively saving precious hours of work. On the structural analysis, Vincent remarked:

SimScale was used extensively to analyze the performance of the new designs including:

• Stress and forces on the connectors under various loading conditions 
• Temperature distribution including peak temperature at various ambient conditions
• Vibration assessment using harmonic analysis
• Use Joule heating inside CFD to analyze the electrical potential, current density, and thermal transfer together. That is perfect for high-power connector simulations.

The subsequent step is validating SimScale’s simulated performance predictions with real-world laboratory tests, an ongoing exercise.