No abstract

Multivariate statistical analysis using principal components can reveal patterns and structures within a data set and give insights into process performance and operation. The output medium is usually a two dimensional screen, however, so it is a challenge to visualize the multidimensional structure of a data set by means of a two-dimensional plot. A method of visualization is described in the form of a hierarchical classification tree that can be used to view the structure within a multivariate principal component model of three or more dimensions. The tree is generated from an unsupervised agglomerative hierarchical clustering algorithm which operates in the score space of the principal component model, and a recursive algorithm to draw the tree. It is readily adaptable to a wide range of multivariate analysis applications including process performance analysis and process or equipment auditing. Its application are illustrated with industrial data sets.

No abstract

Issues regarding steady state power system characteristics when planning large wind farms are investigated. Studies of a specific grid have been performed. A method for finding the maximum wind farm size at a given site is presented.The investigations show that the maximum wind farm capacity is highly dependent on the electrical configuration at the individual windmills. Reactive compensation increases the allowed capacity when using induction generators. Variable speed generators have the best electrical characteristics and give the potential of increasing the maximum wind farm capacity compared to induction generators.Losses in the internal wind farm grid and the external grid are also affected by the electrical configuration as well as the size of the wind farm. A configuration with induction generators and no reactive compensation gives increased losses both in the internal and external grid. Utilizing the grid to the maximum will also increase the losses.Index Terms-Losses, power system simulation, reactive power control, voltage, thermal factors, wind power generation.

Different series compensation applications by using the Magnetic Energy Recovery Switch are reviewed. The Magnetic Energy Recovery Switch is a variable series compensation device characterized by simple configuration and control as well as a large operating range. Three different applications areas are introduced; Load control, generator power capability improvements and series compensation in transmission systems. Load control application seems promising for cases where control of the frequency is not a necessity, such as for fluorescent lamps. By using MERS in series with permanent magnet generators can the output power capability of the generator be increased. At the high power end, MERS is discussed for use as a series compensator in transmission systems, where the power flow can be controlled and increased. In summary, the paper suggests a wider use of series compensation in electrical systems.