MODEL THE COMPLEXITY
A GKN Auto Success Story
GKN optimizes EV inverter performance to offer a competitive product, enhance driving experience and increase driving range.
By Randall Newton
Automotive manufacturing is engaged in a paradigm shift towards electric vehicles (EVs). GKN Automotive intends to be a leader in that shift. The company is recognized for its expertise in optimizing electric drivetrain components.
Using Simcenter™ Amesim™ software, GKN Automotive has streamlined its development processes, significantly reducing time-to-market and the need for costly prototype iterations.
Almost 50 percent of new cars worldwide feature GKN Automotive systems and solutions, which means hundreds of millions of cars with GKN Automotive technology are driven everyday.
Optimizing inverter performance
Developing new designs for high-performance EV inverters is a challenging task. The company realized that optimizing inverter performance was essential to offer a competitive product, enhance the driving experience, and increase the EV's driving range.
Inverter development is centered around the 3-in-1 system, comprising a gearbox, an electric machine and a traction inverter. This transition from mechanical to mechatronic design posed unique challenges, particularly concerning the inverter, the most complex and costly component of the 3-in-1 system. The inverter had to provide the required power, ensure efficiency and remain cost-effective.
In most cases, vehicle manufacturers regard the 3-in-1 system as a black box, delivered as a single, complete solution. In the case of GKN, the gearbox hosts additional features, such as park lock or disconnect systems as well as the basic gear set. The inverter provides the electric machine control functionality.
Suppliers such as GKN must therefore have the ability to deliver components that meet the design and performance specifications set by customers.
“We faced engineering challenges to change from mechanical to mechatronic design,” notes Björn Nemitz, a system engineer at GKN ePowertrain. This shift in design philosophy is both a challenge and an opportunity. Poor design decisions can have a massive negative impact on cost and performance. At the same time, well-considered and carefully implemented decisions on interfaces and internal design can lead to significant performance improvements and cost efficiencies.
GKN relies on Simcenter Amesim software, part of the Siemens Xcelerator business platform of software, hardware and services, for developing and optimizing its traction inverters for electric vehicle 3-in-1 systems.
GKN Automotive was able to utilize Simcenter Amesim's capabilities to conduct comprehensive analysis across multiple product dimensions, including thermal, electrical and mechanical aspects.
Simcenter Amesim allowed GKN Automotive to simulate various aspects ranging from semiconductors to the entire 3-in-1 system. The team analyzed static and dynamic load cycles, electromagnetic compatibility scenarios, safety, failure analysis and complex lifetime cycles.
The ability to create models representative of real systems significantly reduced the reliance on physical tests. Simcenter Amesim's capabilities translated to fewer hardware-in-loop tests and prototype loops, enabling quicker and more cost-effective development processes.
“Simcenter Amesim has helped me to expand my technical expertize regarding the individual components and the system as a whole,” says Nemitz. “I now have a much better understanding of the physical behavior of the components and how they affect each other.”
Driving the future of electric vehicles
GKN Automotive says the successful implementation of Simcenter Amesim has revolutionized their design and development processes. The platform has provided the depth of detail and complexity of analysis needed to optimize the inverter's performance while minimizing overdesign and slashing development costs.
GKN Automotive's adoption of Simcenter Amesim underscores the tool's utility in navigating the automotive industry's transition from combustion engines to EVs.
Through multidimensional simulations, GKN Automotive has enhanced their understanding of how components interact and affect each other. This knowledge is pivotal in making informed decisions early in the development process and aids in producing cutting-edge eDrive technologies.
Nemitz says operational capabilities to be tested can be as complex as needing to solve for a fully loaded vehicle with a trailer, operating at -40 Celsius (°C) ambient temperature, on a steep hill with a nearly depleted battery. Designers must adjust parameters to find the optimum distribution of load between the interconnected components. Nemitz and his team rely on the variety of tests possible in Simcenter Amesim to make sure they achieve an optimal solution.
“GKN has developed standardized models and processes to use in the product development cycle,” comments Nemitz. “That way we can use the simulations for each project right from the start and have a validated base for our design and development.”
As the automotive industry continues to evolve, GKN Automotive's reliance on the digital twin model facilitated by simulation technologies will be a key factor. This approach will enable GKN Automotive to rapidly design and produce high-performance EV components at lower costs, further solidifying their position at the forefront of the eDrive technologies market.
