Search for dissertations about: "negative sequence current"

Showing result 1 - 5 of 17 swedish dissertations containing the words negative sequence current.

2. 1. On Control of Grid-connected Voltage Source Converters - Mitigation of Voltage Dips and Subsynchronous Resonances

   Author : Massimo Bongiorno; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power Electronics; Voltage Source Converter VSC ; Power Quality; Current Controller; Voltage Dip Sag ; Subsynchronous Resonance SSR .;

   Abstract : Custom Power and Flexible AC Transmission Systems (FACTS) denote the application of power electronics in distribution and transmission networks, respectively. Custom Power is the application of power electronics to improve the quality of power distribution for sensitive industrial plants. READ MORE

4. 2. On Power-system Benefits, Main-circuit Design, and Control of StatComs with Energy Storage

   Author : Hailian Xie; Hans-Peter Nee; Lennart Ängquist; Timothy Green; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energy storage; Voltage source converter; VSC; Static synchronous compensation; StatCom; Active power compensation; Phase jump; Voltage dip; Weak network; Flux modulation; Deadbeat current control; Transformer saturation; Dual thyristor converter; dc interface; Electrical engineering; Elektroteknik; Electric power engineering; Elkraftteknik;

   Abstract : Static synchronous compensation (StatCom) is an application that utilizes a voltage source converter (VSC) to provide instantaneous reactive power support to the connected power system. Conventionally, StatComs are employed for reactive power support only. READ MORE

5. 3. On control of cascaded H-bridge converters for STATCOM applications

   Author : Ehsan Behrouzian; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cascaded H-bridge converters; FACTS.; Modular Multilevel Converters MMC ; STATCOM;

   Abstract : Cascaded H-bridge (CHB) converters are today considered the industrial standard for STATCOM applications, mainly due to their small footprint, high achievable voltage levels, modularity and reduced losses. However, there are still areas of research that need to be investigated in order to improve the performance and the operational range of this converter topology for grid-applications. READ MORE

6. 4. Identification and characterisation of SMIM1 variants determining the Vel blood group

   Author : Mikael Kronborg Christophersen; Avdelningen för hematologi och transfusionsmedicin; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Blood groups; Vel blood group system; genetic variation; transcriptional regulation;

   Abstract : The Vel blood group antigen is present on red blood cells from all humans except rare Vel-negative individuals, who can form antibodies to Vel in response to transfusion or pregnancy. It was first described in 1952 as a high incidence antigen, while the molecular background was recently discovered to be a 17-bp deletion in Small Integral Membrane Protein 1, that causes a frame-shift mutation and abolishes SMIM1 expression, thus creating a Vel-negative phenotype. READ MORE

7. 5. Experimental Observations and Theoretical Modeling of Lightning Interaction with Tall Objects

   Author : Helin Zhou; Rajeev Thottappillil; Gerhard Diendorfer; Daohong Wang; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tall objects; Upward lightning initiation; Charge density distribution; Upward positive lightning; Upward bipolar lightning;

   Abstract : This thesis investigates various discharge processes associated with upward lightning initiated from tall objects, both experimentally and theoretically, trying to bridge the knowledge-gap in understanding the mechanisms of the phenomena.Upward lightning initiation has attracted a great deal of interest during recent years due to the proliferation of tall communication towers and wind turbines. READ MORE