Abstract-The paper describes simulations and a live test of the black-start procedure of an industrial power plant in the North of the Netherlands. After a total blackout of the Public Grid in the Netherlands, the restoration process shall start with so-called black-start units. To increase the probability that the re-energizing of the Public Grid indeed succeeds, the Dutch transmission system operator obliges units to prove their blackstart capability by performing a live test.A crucial step in the re-energizing of the Public Grid is the energizing of large transformers. Problems can be expected due to the inrush current of the transformers. For one such generating unit extended simulations of the inrush phenomena of the transformers and calculation of inrush currents and overvoltages were performed. Based on the simulation results well-founded decisions were made on the most suitable start-up procedure. The simulations were followed by live tests of the black-start procedure.

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Abstract--The ongoing liberalization process in Europe together with the growing penetration of renewable energy sources (RES), e.g. wind power, require an internationally oriented transmission planning approach that considers the increased uncertainties in terms of trade, location of generation and output of intermittent RES. This paper identifies and ranks bottlenecks, which is the first step of the transmission expansion planning process of interconnected transmission grids. A round-the-year approach is adopted by combining market simulations with static security analysis. Many combinations of load and generation (including renewables) are created and analyzed, using unit dispatch based on cost optimization. For each combination the branch loadings are determined for normal and contingency situations. A statistical risk-based approach for ranking the most severe bottlenecks is developed. The method is illustrated on a modified New England test system where wind power was added at several buses. A regional analysis and a detailed per-area analysis are presented.Index Terms--bottleneck ranking, load flow analysis, market simulations, multi-criteria analysis, round-the-year approach, power generation dispatch, transmission planning, wind energy.

In the paper, the simulation of the energizing of transformers and more specifically the calculation of inrush currents is dealt with. First, the physical origin of inrush currents is discussed. Then, two different transformers, namely a 20 MVA 10.6/66 kV and a 160 MVA 66/220 kV transformer, are each modelled in two different software packages, namely ATP and DIgSILENT Power Factory. The models are described elaborately and the values of all relevant quantities are given. The models are used to simulate the energizing of the studied transformers from a generator and to investigate the impact of various quantities, such as remanent flux and switching instant. Finally, the simulation results are compared with measurements and it is observed that a satisfactory level of correspondence has been achieved.