Matthias Boesing

Power electronic architectures for electric vehicles

With the aim to asses power electronic architectures for electric vehicles, modeling of power electronics is discussed in this paper. Drive train topologies are introduced, the investigated power electronic components are described, and the modeling process is discussed. On the basis of an example scenario, selected simulation results are presented.

Vibration Synthesis for Electrical Machines Based on Force Response Superposition

A universal and modular approach for synthesizing electromagnetically excited vibrations in electrical machines is presented. The synthesis process uses force responses, i.e., the normalized structural vibration responses for a machines generic set of force excitation shapes. The responses are superposed after scaling by the operating point dependent force excitation amplitudes. This leads to a computationally efficient process. It allows to use detailed structural 3-D models and to synthesize the vibrations in the entire operating range of the machine. For validation, measured and synthesized vibration spectrograms of a run-up test of an interior permanent magnet traction motor are presented.

Exploring a Vibration Synthesis Process for the Acoustic Characterization of Electric Drives

A comprehensive vibration synthesis process for synthesizing the electromagnetically excited acoustic vibrations in electric drives is explored in this paper. The study is performed on a traction drive for a hybrid electric vehicle. The work derives and highlights several key aspects for modeling and assessing the acoustic characteristics of electric drives. The influence of different force excitation shapes on the resulting overall vibration is shown, and the importance of including tangential forces in the synthesis process is highlighted. The resulting operational deflections at selected operating points are analyzed and compared to measurements. The load level dependence of the noise components is investigated. Finally, acoustic maps are introduced as a means to display and compare predicted and measured acoustic characteristics of variable-speed drives. The synthesized acoustic maps are validated by comparison against their measured counterparts.

Exploring a vibration synthesis process for the acoustic characterization of electric drives

A method to efficiently synthesize electromagnetically excited vibrations in electric drives is explored in this paper. The process integrates well into a drive systems design phase and allows to characterize the vibrations over the entire torque-speed range. The study is performed on a traction drive for a hybrid electric vehicle. The influence of different force excitation shapes on the resulting overall vibration is shown and the importance of including tangential forces in the synthesis process is highlighted. The resulting operational deflections at selected operating points are then analyzed. Finally, acoustic maps are introduced as a means to represent and compare predicted and measured acoustic characteristics of speed-variable drives. The synthesized acoustic maps are validated by comparison against their measured counterparts.

Measurement-parameterized synchronous machine model with spatial-harmonics

This paper presents an advanced measurement-parameterized synchronous machine model. The model takes into account saturation, cross coupling and spatial harmonics. The measurement setup, measurement procedure and needed mathematics are derived. The flexible model structure allows to take into account permanent magnet and synchronous reluctance motors. The machine data is also used to determine nonlinear control tables for accurate torque control. Finally, the extracted machine model and torque controller with its control tables and control parameters is evaluated.

Noise-Vibration-Harshness-Modeling and Analysis of a Permanent-Magnetic Disc Rotor Axial-Flux Electric Motor

A drive-system-based modeling approach for electromagnetically excited noise-vibration-harshness (NVH) simulation of a disc rotor permanent-magnetic axial-flux synchronous motor is introduced. The electric motor type requires a 3-D finite-element (FE)-based modeling for electrodynamics and magnetomechanical coupling. The methodic focus relies on orthogonal 3-D Fourier-representations for structural modal displacements and for magnetic force densities. The application of Galerkin-projection based on a supermesh construction between source FE meshes to equidistant 3-D grids is hereby required. A significant data reduction for model parametrization is achieved and a low-rank domain coupling matrix, including a high technical interpretability, is derived. Thus efficient NVH simulations of operation cycles including inverter and control influences can be performed within an order-reduced formulation. This paper is the first to derive a fully 3-D FE-based NVH analysis workflow for electric machines under realistic operating conditions for a routine industrial applicability. The high validity of the methodology is proven by a good agreement to real world measurements.

Modeling inverter-fed three-phase squirrel-cage induction machines including spatial and temporal harmonics

This paper presents a simulation model for voltage-fed 3-phase, unskewed, cage-rotor induction machines. The model includes the effects of machine harmonics due to winding distribution, slotting and saturation. The model demonstrates the influence of various harmonic quantities in the machine and calculates respective electrical and magnetic quantities like currents, flux linkages, magnetic field strength, torque and airgap force. It is an analytical model based on the 2-D machine geometry and material parameters. The model does not require simulated Finite Element Method (FEM) data. It is purposed to be used in ordinary differential equations environment models like Matlab Simulink. The model is validated by comparing simulated and measured stator currents and torque at different operating points. Additionally, stator and rotor currents, as well as torque and the magnetic flux density in the air-gap are compared with FEM simulations.