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This paper describes some theoretical and experimental results obtained in an effort to optimize the Series Resonant Converter (SRC) when used with a loosely coupled transformer for Inductive Coupling Power Transfer (ICPT). The main goal of this work is to define precisely which mode of operation of the power stage is the most efficient. The results also suggest a way to choose the design criteria for the physical parameters (operation frequency, characteristic impedance, transformer ratio, etc.) to achieve that mode of operation. The analysis involves also the investigation of the separated in two halves pot core ferrite transformer, especially the way it changes its magnetizing and leakage fluxes and hence, inductances. It is shown that for the practical values of the separation distance, the leakage inductance remains almost unchanged. Nevertheless the current distribution between the primary and the secondary windings changes drastically due to the large variation of the magnetizing inductance. The analysis has lead to a set of equations with solutions that show graphically the way to an optimized operation of the converter, i.e. higher primary currents and higher transformer ratios to fit in the desired mode.

This paper presents and discusses two case studies in the Portuguese motor vehicle industry – Salvador Caetano’s Ovar Industrial Division (SCOID), a ‘Brownfield site’ with minority Toyota ownership; and Autoeuropa, a ‘Greenfield site’ wholly owned by Volkswagen. Basically, it considers the scope for the meaningful application of ‘Japanese’ organisational methods in these contexts, focusing on the human factor – i.e. as close as possible to the actors on the shop floor. After providing some insights into the Portuguese automotive industry, it profiles both SCOID and Autoeuropa and assesses each of their methods of work, within this balance of commitment between global and local. The main findings reveal the lag that can exist between theoretical models (namely those following a geographical criteria) and the actual practice carried out by manufacturers when tested outside their point of geographical origin.

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A general model for the design and planning of closed-loop supply chains is proposed. The model is both strategic and tactical in nature, containing two levels of decisions: the location of facilities and the planning of production, storage and distribution. Its mathematical formulation is solved using a standard Branch and Bound technique. The model applicability and accuracy are studied on a modified version of an already published case study.

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