Search for dissertations about: "short circuit"

Showing result 6 - 10 of 141 swedish dissertations containing the words short circuit.

2. 6. Aspects on Wind Turbine Protections and Induction Machine Fault Current Prediction

   Author : Marcus Helmer; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; saturation; Induction generator; Short circuit currents; Slip ring Generator; skin effect;

   Abstract : This thesis presents detailed modelling of the induction machine with the main objective being accurate fault current prediction. The thesis focus mainly on mains connected induction machines and the response due to severe disturbances in the supply voltage, such as three-phase short-circuit faults. READ MORE

4. 7. Hydropower generator and power system interaction

   Author : Johan Bladh; Urban Lundin; Rafael Escarela-Perez; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Amortisseur windings; applied voltage test; automatic voltage regulators; damper windings; damping torque; empirical modelling; equivalent circuits; excitation control; finite element method; hydropower generators; power system restoration; power system stability; synchronous machines; self excitation; shaft torque amplification; short circuit test; single machine infinite bus; slip test; standstill frequency response test; subsynchronous oscillations; synchronising torque; synchronous generators; torsional interaction.; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Abstract : After decades of routine operation, the hydropower industry faces new challenges. Large-scale integration of other renewable sources of generation in the power system accentuates the role of hydropower as a regulating resource. READ MORE

5. 8. Fault Behavior of Wind Turbines

   Author : Francesco Sulla; Industriell elektroteknik och automation; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind Turbines; Short-Circuit Currents; Doubly-Fed Induction Generator; Grid Fault Ride-Through; Voltage Support; Weak Grid;

   Abstract : Synchronous generators have always been the dominant generation type in the grid. This fact affected both planning and operation of power systems. With the fast increase of wind power share in the grid in the last decade, the situation is changing. In some countries wind power represents already a consistent amount of the total generation. READ MORE

6. 9. Voltage Dip (Sag) Estimation in Power Systems based on Stochastic Assessment and Optimal Monitoring

   Author : Gabriel Olguin; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; power quality; symmetr?cal components; stochastic methods; impedance matrix; voltage dips; integer optimisation; power systems; short-circuit faults; voltage sags;

   Abstract : This dissertation deals with the statistical characterization of the performance of power systems in terms of voltage dips (sags). It presents a method named voltage dip estimation that extends monitoring results to buses not being monitored. READ MORE

7. 10. Power Estimation and Low Power CMOS Circuit Techniques

   Author : Atila Alvandpour; Linköpings universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : The increasing power consumption due to the high integration rate of VLSI digital CMOS circuits has become a major concern. Many important design issues and parameters are strongly dependent on the power dissipation and the accuracy of its estimated value during the design exploration. READ MORE