Search for dissertations about: "AC steady state"

Showing result 1 - 5 of 14 swedish dissertations containing the words AC steady state.

2. 1. PMU-based State Estimation for Hybrid AC and DC Grids

   Author : Wei Li; Luigi Vanfretti; Hao Zhu; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

   Abstract : Power system state estimation plays key role in the energy management systems(EMS) of providing the best estimates of the electrical variables in the grid that arefurther used in functions such as contingency analysis, automatic generation control,dispatch, and others. The invention of phasor measurement units (PMUs) takes thepower system operation and control into a new era, where PMUs’ high reportingrate and synchronization characteristics allow the development of new wide-areamonitoring, protection, and control (WAMPAC) application to enhance the grid’sresiliency. READ MORE

4. 2. Membrane-based nanocalorimetry for low temperature studies with high resolution and absolute accuracy

   Author : Stella Tagliati; Andreas Rydh; Vladimir M. Krasnov; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Nanocalorimetry; specific heat; membrane-based calorimeter; AC steady state; frequency dependence; thermal link conductance; thermal relaxation; GeAu thermometer; numerical simulations; fysik; Physics;

   Abstract : A differential, membrane-based nanocalorimeter has been designed and constructed for thermal studies of mesoscopic samples at low temperatures. The calorimeter is intended for sample masses from mg to sub-μg and a broad temperature range from above room temperature down to the sub-K region. READ MORE

5. 3. Steady state analysis of HVDC grid in the North Sea with offshore wind power plants

   Author : Kalid Yunus; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; scheduled exchange power; NPV; transmission fee tariff; primary controller; ARIMA; external AC grid connection; secondary supervisory controller; meshed HVDC transmission grid; VSC HVDC; WPP;

   Abstract : In this thesis, some of economical and technical aspects of expanding the HVDC (High Voltage Direct Current) transmission systems in the North Sea are studied at steady state. In the thesis, it is assumed that the expansion of the system is made by connecting WPPs (Wind Power Plants) to the system which is built for power exchange. READ MORE

6. 4. On Techno-economic Assessment of a Multi-terminal VSC-HVDC in AC Transmission Systems

   Author : Feng Wang; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transmission Grid.; Loss minimization; AC DC system; Transmission expansion planning; Multi-terminal VSC-HVDC; Cost minimization; Cost-benefit analysis; Electric power system; Optimal power flow;

   Abstract : The Voltage Source Converter based Multi-Terminal high voltage Direct Current transmission system (VSC-MTDC) is currently considered as an attractive technical option for increased transmission capacity and improved controllability and flexibility of an electric power grid, thanks to its unique performance characteristics, and the possibility of using the extruded XLPE cables. In the planning process of embedding a VSC-MTDC system into an ac transmission grid, one must assess the potential values in terms of improved energy efficiency, i. READ MORE

7. 5. Aspects on measuring electrical current utilizing magnetic zero-flux technique

   Author : Maria Hammarqvist; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Current Transformer; AC Current; Frequency Response; Measurement Uncertainty; Traceability; Zero-Flux Measurement Technique; Zero-Flux;

   Abstract : The utilization of high accuracy measurements of electrical quantities is a prerequisite for the development of modern society. Generally, measurements serve different purposes and hence the criteria for the measurement equipment and method are different. READ MORE