Tiberiu Rusu

Considering half bridge converters for switched reluctance motor drive applications

The aim of the paper is to present an option of using regular half-bridges topology converters for independent driving of multi-phases switched reluctance motors (SRMs). The possibility of using a well-known and accepted topology could represent a cost-related, self-assured and more-efficient way of addressing at least some of the issues regarding the SRM acceptance in practical implementations. In this paper, the general approach, working principles, the first developments and analyses are introduced. Numerical simulations have been done considering the whole drive and the differences between the conventional and the studied converters are highlighted, when applying the converters output voltages to a three-phase 6/4 SRM.

Magnet-based vs. magnet-free electrical machines for low power automotive applications

In his paper he authors present a comparison between magnet-based and magnet-free motors for an oil pump used in automotive applications. From the first category, two inset permanent magnet (IPMs) synchronous motors are chosen whereas the later group of motors is represented by a double stator switched reluctance machine (DS-SRM). The three-phase 12s/8p and 12s/10p IPMs are compared with the four-phase 16/12 DS-SRM in terms of torque capability, power density, efficiency and cost of active materials. Comparisons were conduced both at room and high temperature and assuming two different values for the DC-bus voltage: 12V and 48V. Some rather general remarks are done about the noise vibration and harshness problems (NVH) ha an electrical machine for automotive applications designer has to deal with.

The Effect of Natural Clays Catalysts on Thermal Degradation of a Plastic Waste Mixture

The thermal and catalytic degradation of a plastic wastes mixtures using two types of natural clays catalysts has been carried out in order to obtaining liquid oils with potential use in the chemical industry. Thus, the polymer waste mixture (PWM) of polystyrene (PS), poly (ethylene terephthalate) (PET) and poly (vinyl chloride) (PVC) were thermally degraded at 420 °C in absence and presence of studied catalysts in mass ratio 1:10, catalyst/PWM. The catalysts were characterized by N2 adsorption-desorption isotherms (BET), Scanning Electron Microscopy (SEM) and Fourier-transform infrared spectrometry (FTIR) for determined the structural and textural properties. The degradation of plastic wastes produces gases, liquids and solid residue products. The effect of the catalyst types on the yields and distribution of end-products obtained by thermal and catalytic degradation of mixed plastic waste has been studied. The yields of liquid oils fractions were calculated between 54.98 wt.% and 62.18 wt.%. The liquids and solid products were analyzed by different analytical techniques: gas chromatography mass spectrometry (GC-MS), ultraviolet visible spectroscopy (UV-Vis) and/or FTIR, in order to establish the chemical compositions. The GC-MS results showed that the liquid products contain in principal monoaromatic compounds like styrene, toluene, ethylbenzene or α-methylstyrene. The FTIR and UV-Vis spectra of products indicated the specific vibration bands or transitions between electronic energy levels of the functional groups of the constituent compounds.

Study of winding arrangement and material quality effects on the core losses in high speed switched reluctance machines

The paper presents the analysis of losses of a three-phase, high speed 12/8 switched reluctance motor (SRM), intended to be used in automotive applications. The objective is to investigate by comparison the iron losses considering different types of short pitch winding arrangements, as well as different core laminations, and how much these affect the performance of a SRM having the same structure and working under the same conditions. The flux paths and static characteristics of several configurations are analyzed by means of 2D finite-element method (FEM). The effect of different lamination materials on the iron core losses are also studied. Dynamic simulation results were used to evaluate the performance of different SRM variants.