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The presence of harmonic currents in three-phase distribution networks and the stochastic behavior of unbalanced loads with different power factors are undoubtedly responsible for power quality problems. This paper proposes a novel solution named Cross Phases Hybrid Transformer (CPHT) to address those issues. The CPHT incorporates a conventional distribution transformer into an AC/AC power electronic stage referred to as cross phase module. This new hardware configuration allows to achieve continuous three-phase energy supply of distinct loads as well as high energy quality indexes for diverse distribution networks. The proposed solution has been numerically and experimentally validated by means of simulations carried out in Simulink and with a scaled-down laboratory prototype respectively. The validations consider distinct case studies to show the operative advantages of the CPHT with respect to other topologies reported in the literature.

The new Prevention of Occupational Hazards Act (P.O.H.A.) has aroused great expectation among social workers and health experts who are working in this field. This article contains a critical commentary of the above-mentioned Act. The conclusion is reached that the P.O.H.A. promotes safety and occupational health in work places: its aim is to improve working conditions; although it guarantees the participation of the social worker, it does not allow for co-management in these matters; and that the deficiencies that are found must be overcome by means of the rulings, collective agreements and specific agreements with social workers.