EOMYS provides complete consulting services specialized to solve EV/HEV NVH issues, combining numerical simulations and experimental tests to characterize noise and vibrations due magnetic forces.

EV HEV NVH simulation services

EOMYS developed during its consulting activities MANATEE software specialized on e-NVH fast and accurate simulation at all design stages of electric powertrains and electric motors, including high-end solutions for e-NVH mitigation based on structural or electrical design changes. Simulation can be used during all stages of e-motor development cycle or after manufacturing to troubleshoot acoustic noise and vibration issues.

EV HEV NVH simulation at early design stage

In early design stage, MANATEE software can be used by electromagnetic engineers to quickly rank different e-motor topologies based on simple inputs such as lamination dimensions or slot/pole combinations. Robust NVH design can be carried by comparing different architectures sensitivity to faults or manufacturing tolerances (e.g. eccentricities, uneven magnetization, uneven airgap).

Once the e-motor topology is frozen, MANATEE tools can be used to identify the root cause of resonances. E-motor dimensions can then be optimized to avoid strong resonances between lamination modes and magnetic forces. Noise control techniques such as pole shaping or skewing can be sized with respect to NVH and electromagnetic performances.

EV HEV NVH simulation stage at intermediate stage

Once control strategy is known (e.g. Id/Iq function of speed and PWM strategies), MANATEE can include switching effects so that best switching strategy can be chosen achieving both NVH, sound quality and efficiency objectives.

EV HEV NVH simulation stage at detailed stage

Once a detailed CAD model of the full e-powertrain (housing, stator and rotor, gearbox) is available, MANATEE calculations can be refined to include both air-borne and structure-borne noise. Numerical transfer path analysis outputs include noise and vibrations due to rotor and stator electromagnetic excitations under radial, tangential force wavenumbers. Blocked forces at interfaces can also be calculated to ease prediction of vibration and noise at system level where electric powertrain is integrated.

The CAD model should be preferably fit with EV HEV NVH test results. A rotor beam model can be used to study combined effect of UMP and eccentricity in MANATEE.