Sales of electric vehicles (EVs) are skyrocketing. Driven by technological improvements in powertrains and batteries, environmental regulation, and shifting consumer demand for greener vehicles, global sales of EVs rose by 40 percent last year. And the electrification revolution is only getting started. This growth trend will continue as the cost of owning electric vehicles declines and approaches the cost of internal combustion engine (ICE) vehicles sometime within the next decade.
But for engineers of EVs, green doesn’t come easy. In addition to the design of the individual components (motor, inverter, battery, charging system), they must also consider the interplay between these parts and their effect on the entire system. Each of these components involves complex multiphysics. Designers need to model the fluid flow, thermal fields, structural integrity and electromagnetic effects that drive component performance. At the same time, they can’t ignore consumer comfort. No one wants to drive or ride in a car with an overly noisy motor or hot patches in the car’s cabin caused by heat leaking from the motor or battery.
Because of all the interactive physics, optimizing each of the motors’ components does not guarantee optimization of the entire system. Understanding this, EM-motive GmbH — a designer and manufacturer of electric traction motors — scrapped the “classic” component-focused development process in favor of a simulation-based system design workflow. Instead of designing and testing individual parts and then assembling them, EM-motive created a holistic workflow, which evaluates the multiphysics performance of the entire motor, and accounts for dynamic interactions between components throughout the design process.
The company builds its parametric workflows in ANSYS optiSLANG and uses ANSYS tools that readily transfer the results of one type of simulation (electromagnetic, for example) and set them as boundary conditions for other simulations (e.g., mechanical, fluid or thermal). In this way, it can model the behavior of the e-machine as a single whole, and quickly assess the system-wide impact of even seemingly insignificant design updates. This capability is also appreciated by EM-motive’s customization-seeking customers. The e-motor designer can extract performance indicators — torque, speed, power, rotor inertia, etc. — from a variety of design options and, with the help of simple chart, offer its customers an easy-to-grasp comparative analysis of those options.
The design workflow for an electric vehicle motor must comprise all
of these internal and external components.
Multiphysics simulation that simultaneously considers all physical aspects involved in a motor is critical for EM-motive to achieve its most important objectives: reduced time-to-market and cost. When coupled with ANSYS’ design automation tools and parametric high-performance computing (HPC) solutions, engineers can focus on engineering the design instead of engineering the simulation.