Multiobjective optimization of IPM synchronous motor using response surface methodology and filtered Monte Carlo approach

Permanent Magnet Synchronous Motors offer high efficiency and power density besides low assembly effort and hence have been established in a wide market over the past years. Especially buried magnets enable a superior field weakening ability but require an exceptional design effort. Costly Finite Elements computations are inevitable for consideration of the occurring non-linearity and non-trivial magnet shapes. The Response Surface Methodology can reduce the number of FE runs significantly by introducing an acceptably exact second order regression model based on a few carefully chosen design samples. Instead of commonly used, but time-consuming Evolutionary Strategy methods, the Monte Carlo approach is applied for optimization. Using simple filter algorithms, distinctive Pareto frontiers can be determined quickly and related to their causative motor designs

Magnetic noise reduction of in-wheel permanent magnet synchronous motors for light-duty electric vehicles

This paper presents study of a multi-slice subdomain model (MS-SDM) for persistent low-frequency sound, in a wheel hub-mounted permanent magnet synchronous motor (WHM-PMSM) with a fractional-slot non-overlapping concentrated winding for a light-duty, fully electric vehicle applications. While this type of winding provides numerous potential benefits, it has also the largest magnetomotive force (MMF) distortion factor, which leads to the electro-vibro-acoustics production, unless additional machine design considerations are carried out. To minimize the magnetic noise level radiated by the PMSM, a skewing technique is targeted with consideration of the natural frequencies under a variable-speed-range analysis. To ensure the impact of the minimization technique used, magnetic force harmonics, along with acoustic sonograms, is computed by MS-SDM and verified by 3D finite element analysis. On the basis of the studied models, we derived and experimentally verified the optimized model with 5 dBA reduction in A-weighted sound power level by due to the choice of skew angle. In addition, we investigated whether or not the skewing slice number can be of importance on the vibro-acoustic objectives in the studied WHM-PMSM.Postprint (published version

Disseny optimitzat de màquines elèctriques per a aplicacions a molt baixa velocitat i amb rang de velocitats molt ampli: Transferència de tecnologia

Actualment moltes aplicacions exigeixen rangs de velocitats amplis i, a més, en els darrers anys s’han anat introduint normes i recomanacions que obliguen a obtenir una eficiència mínima en general funció de la potencia útil. En aquest sentit hem anat treballant en les metodologies de disseny de màquines per a incloure aquest dos aspectes.Today some applications need and extended speed range and also the international regulations includes some aspects about minimum efficiency as a function of rated power. Last year we are working in these aspects to include these restrictions on the design of electrical machines.Peer Reviewe

An innovative natural air-cooling system technique for temperature-rise suppression on the permanent magnet synchronous machines

Peer ReviewedPostprint (author's final draft

Optimal pole number for magnetic noise reduction in variable speed permanent magnet synchronous machines with fractional-slot concentrated windings

Peer ReviewedPostprint (author's final draft

Burden resistor selection in current transformers for low power applications

In order to sense AC current with electric isolation in high frequency switching power converters the most simple and low cost solution is to consider a current transformer with a burden resistor. But burden resistor selection is not a simple task because involves a lot of considerations that affect the output voltage and its signal-to-noise ratio and the bandwidth of the measure. In this paper, considering the basic equations of the transformer and applying the Laplace Transformation is obtained a simple model of the current transformer interesting to select burden resistor and even to design the current transformer in case of high frequency applicationsPostprint (published version

A 3-D Pareto-based shading analysis on solar photovoltaic system design optimization

Peer ReviewedPostprint (author's final draft

Rotor shape multi-level design optimization for double-stator permanent magnet synchronous motors

This research presents a rotor shape multi-level-objective optimization designed to reduce the mechanical stress distribution in the rotor core of a double-stator permanent magnet synchronous motor. The second objective is weight minimization performed via a response surface methodology (RSM) with a uniform precision central composite design (UP-CCD) function. The optimal operation point, with a substantial population size, is reached using a Monto Carlo algorithm on the fitted model. The goodness-of-fit for the model is evaluated based on the modified Akaike information criterion (AICc) and the Bayesian information criterion (BIC) with a linear regression approach. To achieve these goals, a multi-level design procedure is proposed for the first time in machine design engineering. All the electromagnetic forces of the machine such as normal, tangential, and centrifugal forces are calculated using 3-D transient finite element analysis (FEA). The outcome of the proposed rotor core optimization shows that the finalized shape of the studied core has significantly smaller weight and mechanical stress, while the electromagnetic performance of the machine has remained consistent with a pre-optimized machine.Peer ReviewedPostprint (author's final draft

A comparative study of Quasi-FEA technique on iron losses prediction for permanent magnet synchronous machines

The paper presents an advanced quasi-FEA technique on the iron losses prediction using Bertotti’s iron loss separation models, in which a curve fitting is taken into account for coefficients calculation of each model. Moreover, the skin effect and saturation consideration are applied in order to check the accuracy through the relative error distribution in the frequency domain of each model from low up to high frequencies 50 to 700 (Hz). Additionally, this comparative study presents a torquespeed-flux density computation that is discussed and presented. The iron loss characteristics of a radial flux permanent magnet synchronous machine (PMSM) with closed-slots and outer rotor topology are also discussed. The quasi-finite-element (FE) analysis was performed using a 2-D and 3-D FEA, where the employed quasi-2-D FEA is proposed and compared with 3-D FEA, and along with experimental verifications. Finally, all the iron-loss models under realistic and non-ideal magnetization conditions are verified experimentally on a surface-mounted PMSG for wind generation application.Peer ReviewedPostprint (published version

Iron loss prediction using modified IEM-formula during the field weakening for permanent magnet synchronous machines

Peer ReviewedPostprint (published version