Grid-friendly connecting of constant-speed wind turbines using external resistors

In this paper, an alternative method of connecting fixed-speed wind turbines, with active pitch mechanisms or variable-slip generators, is proposed and evaluated. Instead of using the conventional soft starter, external resistors are used. The method was evaluated via laboratory tests on a 15-kW machine and theoretically on a 1-MW wind turbine. The proposed method causes smaller grid power quality impact, especially on inductive grids, compared with soft starters. This means that it will be possible to install constant-speed wind turbines to weaker grids using this method.     

Implementation of a self-timed segmented bus

We propose an asynchronous structure for implementation on a SoC. An intersegment topological arrangement preserves parallelization and, through a so-called central arbiter, efficiently organizes communication with high signaling speed in the proposed structure. Researchers proposed the concept of segmenting buses primarily for multicomputer architectures. More recent approaches address on-chip implementation of segmented buses. We present an asynchronous segmented-bus architecture targeted for the modular design of high-performance SoC applications. The structure not only enables faster operation than a conventional bus system but also offers lower power consumption per transferred data item. This is possible because segmentation is realized in such a way that the majority of data transfers in the system are intrasegment transactions on relatively short wires with low or moderate capacitive loads.     

A Distributed State Estimator Utilizing Synchronized Phasor Measurements

With the creation of balancing authorities by the North American Reliability Council that span large portions of the North American interconnection, and stringent requirements for real time monitoring of power system evolution, faster and more accurate state estimation algorithms that can efficiently handle systems of very large sizes are needed in the present environment. This paper presents a distributed state estimation algorithm suitable for large-scale power systems. Synchronized phasor measurements are applied to aggregate the voltage phase angles of each decomposed subsystem in the distributed state estimation solution. The aggregated state estimation solution is obtained from the distributed solution using a sensitivity analysis based update at chosen boundary buses. Placement of synchronized phasor measurements in the decomposed subsystems is also investigated in this paper. Test results on the IEEE 118-bus test bed are provided     

The hot blow forming of AZ31 Mg sheet: Formability assessment and application development

The hot blow forming of magnesium sheet offers significant opportunity for forming complex, lightweight parts for automotive applications. This paper characterizes the elevated-temperature formability of AZ31 magnesium sheet materials and the effect of processing conditions on the performance of these materials. In addition, magnesium sheet application development at General Motors Corporation is reviewed.     

Study of thermal effects and self-heating phenomena in planar power SOI MOS transistors

Heat removal problems, thermal effects, and self-heating phenomena occurring during operation of planar power SOI MOS transistors are considered. Using device-technological simulating methods, the transistor characteristics and safe operation range were studied. It was shown that limitations of the safe operation range are mostly associated with structure self-heating rather than with the parasitic bipolar transistor.     

Robust Distributed Source Coding

We consider a distributed source coding system in which several observations must be encoded separately and communicated to the decoder by using limited transmission rate. We introduce a robust distributed coding scheme which flexibly trades off between system robustness and compression efficiency. The optimality of this coding scheme is proved for various special cases.     

Cooling and Solidification of Melted Drops in an Immiscible Cooling Medium

The cooling and solidification of melted drops during their movement in an immiscible cooling medium is widely employed for granulation in the chemical industry, and a study of these processes to provides a basis for the design of the granulation tower height and the temperature of the cooling medium is reported. A physical model of the cooling and solidification of the drop is established and the numerical calculation is performed. The influences of the key factors in the solidification, i.e., Bi number, drop diameter, temperature of the cooling medium, etc. are presented. The cooling and solidification during wax granulation in a water‐cooling tower and during urea granulation in an air‐cooling tower (spraying tower) are described in detail. Characteristics of the solidification and temperature distribution within the particle at different times are shown. The model and calculations can be used for structure design of the granulation tower and optimization of the operation parameters.     

Evaluation of ProKappa

ProKappa is an expert system tool kit developed by IntelliCorp in C using X-Windows for graphical interface. The SUN 3 or 4 version costs $9995/£7000 and $2595/£1800 for the interactive C environment.
This review covers ProKappa version 1.1, installed on a colour SUN SPARC Station 1 with the minimum recommended values of 12 Mb of memory and 30 Mb of swap space.
IntelliCorp can be contacted in the USA at 1975 El Camino Real West, Mountain View, CA 94040-2216 (+1 (415) 965-5500) and in the UK at 10 Jewry Street, Winchester, Hampshire SO23 8RZ (+44 (0)962 735348).