Essays about: "low frequency currents"

Showing result 16 - 20 of 22 essays containing the words low frequency currents.

  1. 16. Shaft Current Protection

    University essay from KTH/Industriella informations- och styrsystem

    Author : Tin Rabuzin; [2015]
    Keywords : shaft current; Rogowski coil; generator protection; Merging Unit; process bus; axelströom; lagerströom; Rogowskispole; generatorskydd; Merging Unit; process bus;

    Abstract : Shaft current protection in hydro and turbo generators is an important generatorprotection issue. Currents owing in the generator shaft might damagegenerator bearings which, in turn, could reduce operating time and cause largenancial losses. Therefore, it is important to prevent operation of the generatorunder conditions of high shaft currents. READ MORE

  3. 17. Performance Analysis of Unskewed Asymmetrical Rotor for LV Induction Motors

    University essay from KTH/Elektrisk energiomvandling

    Author : Usman Shaukat; [2012]
    Keywords : Induction motor; skewed rotor; inter-bar currents; starting performance; asymmetrical rotor slots; 2D FEM; synchronous torques.;

    Abstract : This master thesis presents a comparative analysis of the starting performance and losses at rated operation for a 15 kW, 4-pole industrial induction motor, mounted with standard skewed, unskewed and unskewed asymmetrical die-cast aluminium rotors through measurements and simulations. It is a well-known fact that rotor skewing suppresses the synchronous torques at low speeds and also reduces the audible noise of the machine. READ MORE

  4. 18. FPGA Based Sensorless Control of a Permanent Magnet Synchronous Motor

    University essay from KTH/Elektrisk energiomvandling

    Author : Ali El Hafni; [2012]
    Keywords : ;

    Abstract : Field Oriented Control (FOC) has proven to be a high performance and robust control strategy for electrical drives. However the states of the machine, namely speed and/or position, have to be measured in this control strategy. READ MORE

  5. 19. Investigation of Fast High Voltage PDC Measurement based on a Vacuum Reed-switch

    University essay from KTH/Elektroteknisk teori och konstruktion

    Author : Zeeshan Talib; [2011]
    Keywords : step voltage; polarization and depolarization current; vacuum reed switch.;

    Abstract : The diagnostic technique, polarization and depolarization current (PDC) is useful for insulation testing. It requires applying a DC step voltage to the test sample and measuring the current. To measure fast PDC phenomena a fast step is needed. One way of applying a fast high voltage step is to use power electronic switches. READ MORE

  6. 20. ANALYSIS, IMPLEMENTATION AND EXPERIMENTAL EVALUATION OF A PHASE SHIFTED PWM CONTROL SYSTEM FOR A MODULAR MULTILEVEL CONVERTER

    University essay from KTH/Elektrisk energiomvandling

    Author : Juan Colmenares; [2011]
    Keywords : ;

    Abstract : Nowadays, it is problematic to connect only one power semiconductor switch directly to the grid due to the high voltage range. In order to solve this difficulty, a new type of power converter has been introduced as a solution in high power applications. READ MORE