Power Grid

One critical task in any wind power interconnection study involves the modelling of wind turbines. This paper provides the most basic yet comprehensive time–domain wind turbine model upon which more sophisticated models along with their power and speed control ...

1. BACKGROUND Swedish nuclear plants are slowly being shut down as a result of a referendum in 1980. During the years after the referendum, four nuclear reactors were completed and taken into operation. The nuclear power then covered 50% of the Swedish production capacity resulting in large over capacity, which meant inexpensive electricity. For many years thereafter direct electrical space heating was the only feasible option. This development continued until direct electrical heating was used for about 30% of all space heating in Sweden. Swedish consumer prices were then about one third of that in most European countries. The much later deregulation of the electrical market and connection of the power grid to other European countries meant that Swedish consumer prices increased rapidly. Within a few years the prices are expected to be at the same level all over Europe and direct space heating is no longer a feasible alternative. This is why it is so attractive to Swedes to use heat pumps to reduce their electricity consumption. The present Swedish energy policy aims to a changeover from the use of prime energy sources to renewables. This is partly because of international agreements on the reduction of greenhouse emissions and partly to obtain a more independent energy system. Since the use of heat pumps mean that the electrical consumption is reduced by 70% and also means less emission to the atmosphere, heat pump systems have been encouraged by subsidies. This present subsidy, which covers about 15% of the investment, has been on and off during the last decades. Now, the new EU directive on energy efficient buildings offers a platform for the promotion of thermal energy storage (TES) technology in Europe. Therefore HVAC engineers and civil engineers look for new methods to reduce electricity consumption and improve energy performance in new and existing buildings.

Cybersecurity of the substations in a power system is a major issue as the substations become increasingly dependent on computer and communication networks. This paper is concerned with anomaly detection in the computer network environment of a substation. An anomaly inference algorithm is proposed for early detection of cyber-intrusions at the substations. The potential scenario of simultaneous intrusions launched over multiple substations is considered. The proposed detection method considers temporal anomalies. Potential intrusion events are ranked based on the credibility impact on the power system. Snapshots of anomaly entities at substations are described. Simulation results using the modified IEEE 118-bus system have shown the effectiveness of the proposed method for systematic identification. The result of this research is a tool to detect cyber-intrusions that are likely to cause significant damages to the power grid.