In this article, the influence of electropulsing on the machinability of steel S235 and aluminium 6060 has been studied during conventional and electropulsing-assisted turning processes. The machinability indices such as chip compression ratio ξ, shear plane angle ϕ and specific cutting energy (SCE) are investigated by using different cutting parameters such as cutting speed, cutting feed and depth of cut during electrically-assisted turning process. The results and analysis of this work indicated that the electrically-assisted turning process improves the machinability of steel S235, whereas the machinability of aluminium 6060 gets worse. Finally, due to electropluses (EPs), the chip compression ratio ξ increases with the increase in cutting speed during turning of aluminium 6060 and the SCE decreases during turning of steel S235.

Specific energy consumption is an important indicator for a better understanding of the machinability of materials. The present study aims to estimate the specific energy consumption for abrasive metal cutting with ultra-thin discs at comparatively low and medium feed rates. Using an experimental technique, the cutting power was measured at four predefined feed rates for S235JR, intermetallic Fe-Al(40%), and C45K with different thermal treatments. The variation in the specific energy consumption with the material removal rate was analyzed through an empirical model, which enabled us to distinguish three phenomena of energy dissipation during material removal. The thermal treatment and mechanical properties of materials have a significant impact on the energy consumption pattern, its corresponding components, and cutting power. Ductile materials consume more specific cutting energy than brittle materials. The specific cutting energy is the minimum energy required to remove the material, and plowing energy is found to be the most significant phenomenon of energy dissipation.

Outside-spin brushless D.C. motors are an alternative to conventional D.C. brush permanent magnet motors, especially in applications that require low power and costs and in which high inertia effects are advantageous. This paper presents a procedure for computing power losses in these kinds of machines. Expressions are derived for predicting copper losses, power interrupter losses, stator iron losses in the tooth and in the yoke, mechanical losses, friction and windage. Stray load losses are also considered and evaluated from previous measurements in outside-spin brushless D.C. motors. The results obtained from the approach proposed are compared to those measured on existing motors, showing a good agreement.

Abstract. This paper compares the environmental and life cycle impact of one switched reluctance motor (SRM) drive and two inverter-fed induction motor (IM) drives. The study was carried out according to the Directive on the Ecodesign of Energy-Using Products (EuP 2005/32/EC) and following the Methodology for the Ecodesign of Energy-Using Products (MEEUP). The following base-case models were used: an IM (Eff3), an IM (Eff1) and an 8/6 SRM. All of these base-case models are rated at 1.5 kW of output power and are considered to be representative of the low-power range. The analysis shows that SRM drive has a lower environmental impact than the IM drives and offers a high savings potential, comparable to, or even greater than that of the IM (Eff1) in the use phase.

A current-controlled switched reluctance motor drive for variable speed applications with efficiency optimization is presented. Firing angles are computed online, the turnon is calculated by means of the rule of Bose, and the turn-off is calculated using the general theory of the optimal turn-off angle proposed by Gribble. In steady state operation, the initial selection of firing angles is fine-tuned by means of an algorithm that minimizes the input power of the drive. An efficiency and electrical energy consumption comparison with a commercial vector-controlled induction motor drive of the same size is also included. Experimental results show that the proposed switched reluctance motor drive is a good choice for applications that require slow varying loads and energy savings.