Virtual two axes strategy for speeding up the determination of the reference current in single phase active power filters.

Virtual two axes or orthogonal transformation technique instigated by Akagi in 1984 for the investigation of the novel terminology of instantaneous power in three phase power systems and extended by Dobrucky and Pokorny in 1999 for the determination of the instantaneous power in single phase power systems, is utilised in this paper for the fast evaluation of the harmonic distortion and reactive compensating currents in single phase shunt active power filters. Expressions for these currents under different compensating conditions are derived in this paper. Control strategies are utilised to implement these expressions. This results in providing excellent transient response of the filter which is demonstrated experimentally. This fast dynamic response is achieved via the rapid evaluation of the compensating current using a digital signal processor when the two axes strategy is used

Decentralised Power Active Filters

This paper deals with a decentralised power active filter control based on the separated computation of reference current for each active filter operating under determinated harmonic frequency. The basic principle of such controlled active filter is explained. It is shown how the nth hamonic component of the reference current can be calculated. Simulation results are shown on the end of the paper

Single-Phase Power Theory Using Orthogonal Transformations

The paper deals with the new method of power analysis of single-phase power electronic systems. Using a new particular transform theory the ordinary single-phase system can be transformed into equivalent two-axis orthogonal one. The new original thought is based on the idea that ordinary single-phase quantily can be complemented by fictious second phase so that both of them will create orthogonal system, as it usual in three-phase systems. Application of the above theory makes this possible to use complex methods of analysis as instantaneous reactive power method, which have not been usable for single-phase systems so far. All types of the power, active and reactive, can be determined by this way

Mapping and load balancing on distributed memory systems

Two kinds of tools are necessary to optimise the use of available resources by the execution of parallel programs on distributed memory systems: mapping and load balancing tools. A mapping tool is well suited for programs whose behaviour is predictable while for many "real applications", it needs to be complemented by a dynamic load balancing tool. Both tools are currently investigated to be included in the programming environment designed by the SEPP COPERNICUS project. I

Dobrucky M.: Flood Forecasting in CrossGrid project

Abstract. This paper presents a prototype of flood forecasting system based on Grid technologies. The system consists of workflow system for executing simulation cascade of meteorological, hydrological and hydraulic models, data management system for storing and accessing different computed and measured data, and web portals as user interfaces. The whole system is tied together by Grid technology and is used to support a virtual organization of experts, developers and users. 1

Dissemination and exploitation of Grids in earth science

The Earth Science (ES) community has two major IT related concerns: Modeling, which requires vast amounts of computational resources, and exploration and production of large shared data sets. Both can be accomplishable by Grid infrastructure. Grid or Grid computing is a metaphor name for making computer power as easy to access as an electric power Grid1). Different Grid middleware software solutions exist and are being developed. DEGREE (Dissemination and Exploitation of Grids in Earth sciencE) aims to disseminate and promote uptake of Grid in ES and to create a bridge between ES and Grid communities to ensure the next Grid generation will integrate ES application requirements in the middleware and services. In order to achieve this, DEGREE will: identify key ES requirements, disseminate ES application requirements to Grid projects, evaluate Grid middleware tools and standards regarding ES requirements and provide feedbacks to Grid developers. In order to convey require ments to the Grid community, test suite specifications are developed. A test suite specification consists of documentation and an application suitable for testing, including the data needed. Eight test suite specifications are developed and made available by DEGREE for Grid middleware developers. Results will be used to support the development of the ES Grid vision