Browsing by Author "Karugaba, Sosthenes"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Open Access
    Analysis of multi-terminal unified power flow controller for power transfer
    (IEEE, 2008-09) Omoigui, Michael; Karugaba, Sosthenes; Ojo, Olorunfemi
    The paper reports the results of analysis of a multi-terminal UPFC used for power transfer and stability improvement of power systems. The analysis employed abc to qd0 transformation technique to obtain a time-invariant equation describing the system. A simulation of a-two transmission network rated at 20 and 15 MVA at 33 kV was investigated. Results confirm that converters rated appropriately can be used to transfer power between the lines. Converter power and current optimization were carried out to determine their operational limits.
  • No Thumbnail Available
    Item
    Open Access
    Dynamic and steady-state operation of a five phase induction machine with an open stator phase
    (IEEE, 2008-09) Karugaba, Sosthenes; Olorunfemi, Ojo; Wang, Ge; Omoigui, Michael
    The analysis of an open phase fault for a five phase induction motor is presented. A circuit based model is developed which can help to predict not only the steady-state performance but also the dynamics including the pulsating torque and to evaluate the small-signal stability of the faulted machine. This is made possible by the utility of the harmonic balance technique on the model of the machine in the stationary reference frame. The resulting model is used in determining the small-signal stability of the five-phase induction motor under open-phase fault. At low speeds the machine exhibits instability on the rotor flux linkages but it is stable at higher speeds. Simulation results and steady state results are presented which also predict the speed harmonic components as well as the torque pulsations.