Vehicle Design

In this document the work carried out as part of the HEFT project with regards to the deveopment of an ultra-light motor design for segment A+B. The multi-layer rotor topology makes possible to reduce de usage of permanent magnet leading to an important saving in the rare earth elements. Wave winding techcnology allows to develop compact and efficient stator. End winding length is reduced and high frequency losses are reduced in the copper. Involving all these techonologies a high power density motor is developed.
In this document the following issues will be covered:
1. Design Process (Design Methodology and Procedure to motor performances evaluation).
2. Preliminary sizing of the motor.
3. Optimization of the rotor
4. Continuous service evaluation.
5. Final performances evaluation and KPIs computation.

This paper presents a fast and accurate state-space model for synchronous machines taking into consideration the machine geometry, material non-linearities and core losses. The model is first constructed by storing the solutions of multiple static finite element (FE) simulations into lookup-tables (LUTs) to express the stator flux linkages as functions of the state variables, i.e., the winding currents and the rotor position. Different approaches are discussed to include the core loss into the model. A novel approach is presented for constructing a pre-computed LUT for the core loss as a function of the state variables and their time derivatives so that the loss can be directly interpolated when time-stepping the state-space model. The Simulink implementation of the proposed core-loss model shows a good match with time-stepping FE results with a 120-fold speedup in computation. In addition, comparison against calorimetric loss measurements for a 150-kVA machine operating under both sinusoidal and pulse-width modulated voltage supplies is presented to validate the model accuracy.