Several large offshore wind power plants (WPP) are planned in the seas around Europe. VSC-HVDC is a suitable means of integrating such large and distant offshore WPP which need long submarine cable transmission to the onshore grid. Recent trend is to use large wind turbine generators with full scale converters to achieve an optimal operation over a wide speed range. The offshore grid then becomes very much different from the conventional power system grid, in the sense that it is connected to power electronic converters only. A model of the wind power plant with VSC-HVDC connection is developed in PSCAD for time-domain dynamic simulation. This paper presents the modeling and simulation of such a system. A single line to ground fault has been simulated and fault currents for the grounded and ungrounded offshore grid system are obtained through simulation and then compared.
The depth-integrated shallow water equations are frequently used for simulating geophysical flows, such as storm-surges, tsunamis and river flooding. In this paper a parallel shallow water solver using an unstructured high-order discontinuous Galerkin method is presented. The spatial discretization of the model is based on the Nektar++ spectral/hp library and the model is numerically shown to exhibit the expected exponential convergence. The parallelism of the model has been achieved within the Cactus Framework. The model has so far been executed successfully on up to 128 cores and it is shown that both weak and strong scaling are largely independent of the spatial order of the scheme. Results are also presented for the wave flume interaction with five upright cylinders.
ABSTRACT: Denmark is among the more loyal European Union (EU) member states when it comes to national implementation of the Common Fisheries Policy (CFP). However, even in Denmark several mechanisms contribute to sub-optimal implementation of the CFP. Looking at implementation problems for a relatively loyal member state, this chapter sheds critical light on national implementation of the CFP in the EU as a whole. The chapter initially provides a description of the institutional set-up for fisheries policy-making and implementation in Denmark, including a short historical account of the development of the Danish fisheries and their management since 1983. Subsequently, the chapter provides an understanding of the mechanisms and processes behind the Danish implementation of fisheries policy, arguing that these mechanisms and processes have led to a situation where the goals agreed at the EU level are supplemented or even replaced by national priorities. The chapter concludes that in order to capture the domestic politics associated with CFP implementation in Denmark, it is important to understand the policy process as a synergistic interaction between dominant interests, policy alliances/networks and prevailing discourses. The inability of the EU to ensure that the conservation goals agreed at the EU level are loyally pursued during national implementation is one of the reasons why the EU has been struggling to keep fishing mortality rates at a sustainable level.