ABB Ltd

About: ABB Ltd is a company organization based out in Zurich, Switzerland. It is known for research contribution in the topics: Voltage & Signal. The organization has 6222 authors who have published 6852 publications receiving 83994 citations.

Adaptive Critic Design-Based Dynamic Stochastic Optimal Control Design for a Microgrid With Multiple Renewable Resources

Abstract: This paper proposes a three-layer optimization and an intelligent control algorithm for a microgrid with multiple renewable resources. A dual heuristic dynamic programming-based system control layer is used to ensure the dynamic performance and voltage dynamics of the microgrid as the system operation conditions change. A local layer maximizes the capability of the photovoltaic (PV) wind power generators and battery systems, and a model predictive control-based device layer increases the tracking accuracy of the converter control. The proposed control scheme, system wide adaptive predictive supervisory control (SWAPSC) smooths the output of PV and wind generators under intermittencies, maintains bus voltage by providing dynamic reactive power support to the grid, and reduces the total system losses while minimizing degradation of battery life span. Performance comparisons are made with and without SWAPSC for an IEEE 13 node test system with a PV farm, a wind farm, and two battery-based energy storage systems.

Method for operating a combustion chamber of a gas turbine

Abstract: In a method for operating a silo combustion chamber (A) of a gas turbine, this combustion chamber is equipped with a number of premixing burners (B), these burners being arranged so that they are subdivided in groups within the combustion chamber (A). At least one group is equipped with controllable premixing burners. Very high demands are made on the quality of the combustion during the operation of such a combustion chamber (A), particularly in the full-load range, in order to meet the stringent NOx emission regulations. For this purpose, the last group to be switched on is controlled at full load in accordance with the ambient conditions. A load control system also acts at part load. By this means, it is possible to prevent a fluctuation of the NOx emissions due to the varying ambient conditions.

Voltage regulation optimization

Abstract: A voltage regulation optimization (VRO) system receives inputs from a DCS or other distribution network control/monitoring system. The VRO then calculates optimized control commands for various network devices including the controllable taps of voltage regulating transformers.

Press pack power semiconductor module

Abstract: The high-power press pack semiconductor module (1) comprises a layer (3, 4), which is brought into direct contact with one or both of the main electrodes of the Si semiconductor chip (2), said layer being made of a metal matrix composite material whose coefficient of thermal expansion can be tailored to a value either close to or matching that of Si.

Dielectric Properties of Epoxy- ${\rm Al}_{2}{\rm O}_{3}$ Nanocomposite System for Packaging Applications

Abstract: In recent times, there has been an ever-growing need for polymer-based multifunctional materials for electronic packaging applications. In this direction, epoxy-Al2O3 nanocomposites at low filler loadings can provide an excellent material option, especially from the point of view of their dielectric properties. This paper reports the dielectric characteristics for such a system, results of which are observed to be interesting, unique, and advantageous as compared to traditionally used microcomposite systems. Nanocomposites are found to display lower values of permittivity/tan delta over a wide frequency range as compared to that of unfilled epoxy. This surprising observation has been attributed to the interaction between the epoxy chains and the nanoparticles, and in this paper this phenomenon is analyzed using a dual layer interface model reported for polymer nanocomposites. As for the other dielectric properties associated with the nanocomposites, the nano-filler loading seems to have a significant effect. The dc resistivity and ac dielectric strength of the nanocomposites were observed to be lower than that of the unfilled epoxy system at the investigated filler loadings, whereas the electrical discharge resistant properties showed a significant enhancement. Further analysis of the results obtained in this paper shows that the morphology of the interface region and its characteristics decide the observed interesting dielectric behaviors.