No abstract

Abstract. Influence of the slot opening width and rotor pole radius on the cogging torque and total torque developed by a three-phase permanent magnet synchronous motor (PMSM) is investigated. The number of motor poles and number of stator slots are fixed. Finite element technique is used for the computation of machine characteristic. Core saturation is directly considered in the magnetic field calculation. Formulation based on two methods, virtual work and Maxwell stress tensor is used to find the torque.

Rural Smart Grids enables the incorporation of distributed generation as while as the development of the rural communities. In this paper Smart Grid characteristics are presented and challenges of its integration in the network are analysed. Differential characteristics of Rural Smart Grids are summarized and areas that should be investigated to achieve their high scale implementation are pointed out.

This paper presents a hydrogen powered hybrid solid oxide fuel cell-steam turbine (SOFC-ST) system and studies its optimal operating conditions. This type of installation can be very appropriate to complement the intermittent generation of renewable energies, such as wind generation. A dynamic model of an alternative hybrid SOFC-ST configuration that is especially suited to work with hydrogen is developed. The proposed system recuperates the waste heat of the high temperature fuel cell, to feed a bottoming cycle (BC) based on a steam turbine (ST). In order to optimize the behavior and performance of the system, a two-level control structure is proposed. Two controllers have been implemented for the stack temperature and fuel utilization factor. An upper supervisor generates optimal set-points in order to reach a maximal hydrogen efficiency. The simulation results obtained show that the proposed system allows one to reach high efficiencies at rated power levels.

Abstract. This work presents an evaluation methodology of electrical losses in the collector systems for different topologies considered nowadays in large offshore wind parks. Taking into account the current situation of the offshore collector systems, a summary about schemes employed in commissioned wind farms is presented. Electrical layout plays a key role in order to cut down Levelized Cost of Energy (LCoE). Based on the calculus of electrical losses, the authors select the optimum design of the array of the wind farm combined with the most adequate rated power offshore turbines. Power losses evaluation is verified with real cable data sheets and the methodology is applied to a real wind farm in construction.