Sökning: "voltage gradient"

Visar resultat 1 - 5 av 25 avhandlingar innehållade orden voltage gradient.

  1. 1. Voltage Transients in the Field Winding of Salient Pole Wound Synchronous Machines : Implications from fast switching power electronics

    Författare :Roberto Felicetti; Urban Lundin; Jon Kjellin; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; apparent resistance; cable modeling; current control; transmission line model; eddy currents; field winding; frequency analysis response; Fourier Transform; impedance mismatch; main inductance; overvoltage; parasitic capacitance; partial discharge; quality factor; ringing; slew rate; stray inductance; voltage gradient; winding resonance frequency;

    Sammanfattning : Wound Field Synchronous Generators provide more than 95% of the electricity need worldwide. Their primacy in electricity production is due to ease of voltage regulation, performed by simply adjusting the direct current intensity in their rotor winding. LÄS MER

  3. 2. Capacitive Mixing for Extracting Concentration Gradient Energy

    Författare :Zhi Zou; Longcheng Liu; Chia-Hung Hou; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; capacitive mixing; salinity gradient energy; salt difference energy; electric double layer; flow electrode CapMix; kapacitiv blandning; salthaltsgradientenergi; saltskillnadsenergi; elektriskt dubbelskikt; flödeselektrod CapMix.; Chemical Engineering; Kemiteknik;

    Sammanfattning : Capacitive mixing (CapMix) is a renewable method of extracting energy from the salinity gradient energy (SGE) between seawater and freshwater. The classical CapMix systems using solid electrodes generate electricity by periodically circulating seawater and freshwater into the CapMix system. LÄS MER

  4. 3. Run-Up Transient Analysis for Salient Pole Wound Field Synchronous Motors : Field winding and power electronics implications for a smoother and cooler asynchronous start

    Författare :Roberto Felicetti; Urban Lundin; Andreas Binder; Uppsala universitet; []
    Nyckelord :apparent resistance; cable modeling; current control; transmission line model; eddy currents; field winding; frequency analysis response; Fourier Transform; impedance mismatch; main inductance; overvoltage; parasitic capacitance; partial discharge; quality factor; ringing; slew rate; stray inductance; voltage gradient; winding resonance frequency; asynchronous start; run-up; torque ripple; reluctance torque; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : Salient Pole Wound Field Synchronous Machines have better efficiency at full load than asynchronous machines of the same capability. Moreover, where asynchronous machines need inherently to draw a magnetizing current from the grid, Salient Pole Wound Field Synchronous Machines can work efficiently at unity power factor. LÄS MER

  5. 4. On Deep Machine Learning Based Techniques for Electric Power Systems

    Författare :Ebrahim Balouji; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Deep Learning; Cable faults; phase locked loop; Flicker; Harmonics and Interharmonics; Reinforcement learning; Voltage Dip; Active Power filter; Machine Learning; Voltage fluctuation; Partial Discharges;

    Sammanfattning : This thesis provides deep machine learning-based solutions to real-time mitigation of power quality disturbances such as flicker, voltage dips, frequency deviations, harmonics, and interharmonics using active power filters (APF). In an APF the processing delays reduce the performance when the disturbance to be mitigated is tima varying. LÄS MER

  7. 5. Chloride Homeostasis in Central Neurons

    Författare :Tushar Yelhekar; Staffan Johansson; Michael Druzin; Merab Kokaia; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; chloride concentration; current-voltage relation; interpolation; voltage ramp; reversal potential; [Cl–]i recovery; KCC2; extracellular matrix; GABAA receptor; chloride leak conductance; neurosteroid; fysiologi; Physiology;

    Sammanfattning : The overall aim of the present thesis is to clarify the control of intracellular chloride homeostasis in central neurons, because of the critical role of chloride ions (Cl–) for neuronal function. Normal function of the central nervous system (CNS) depends on a delicate balance between neuronal excitation and inhibition. LÄS MER