Search for dissertations about: "Starting current"

Showing result 1 - 5 of 196 swedish dissertations containing the words Starting current.

2. 1. On Inter-bar Currents in Induction Motors with Cast Aluminium and Cast Copper Rotors

   Author : Alexander Stening; Chandur Sadarangani; Ola Aglén; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Induction motors; Inter-bar currents; Copper rotors; Aluminium rotors; Starting torque; Asynchronous torques; Starting current; Stray losses; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

   Abstract : This thesis presents a study of the effects of inter-bar currents on inductionmotor starting performance and stray-load losses. The work is focused on theperformance differences between aluminium and copper casted rotors.A method to predict the stator current when starting direct-on-line isdeveloped. READ MORE

4. 2. Studies on Current Commutation in Hybrid DC-breakers

   Author : Jesper Magnusson; Göran Engdahl; Magne Runde; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Commutation; Hybrid DC-breakers; Electrical Engineering; Elektro- och systemteknik;

   Abstract : Compared to conventional AC-circuit breakers, a DC-breaker has to act fast and force the current down to zero. Many different DC-breaker topologies are available, and this thesis is focused on the hybrid DC-breaker comprising a mechanical switch and high power semiconductors. READ MORE

5. 3. Zero and Multi-Dimensional Modeling of Internal Combustion Engines with respect to Ion Current and Soot Formation

   Author : Abdelhadi Ahmedi; Institutioner vid LTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; engine knock; pollutant emissions; detailed chemical kinetics; thermal ionization.; ion current sensor; method of moments; ionization; soot formation oxidation; modeling; auto-ignition; Spark ignition engine; diesel engine;

   Abstract : The work presented in this thesis can be divided into the three following fields of investigation: First of all the ionization model developed in this thesis is meant to simulate the thermal ionization process or the so-called second peak. Equilibrium assumptions have been adopted for the modeling of the thermal ionization, in which Saha’s equation was derived for singly ionized molecules. READ MORE

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

   Author : Roberto Felicetti; Urban Lundin; Andreas Binder; Uppsala universitet; []
   Keywords : 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;

   Abstract : 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. READ MORE

7. 5. VSC-HVDC for Industrial Power Systems

   Author : Cuiqing Du; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; voltage dips; vector controller; VSC-HVDC; outer controller; current limit; industrial power systems.;

   Abstract : The recent developments in semiconductors and control equipment have made the voltage source converter based high voltage direct current (VSC-HVDC) feasible. Due to theuse of VSC technology and pulse width modulation (PWM) the VSC-HVDC has a number of potential advantages as compared with classic HVDC, such as short circuit current reduction, rapid and independent control of active and reactive power, etc. READ MORE