Department of Electrical Engineeering

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Browsing Department of Electrical Engineeering by Subject "amplifiers"

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    High Power Switch Mode Linear Amplifiers for Flexible AC Transmission System
    (IEEE Transactions on Power Delivery, 1996) Mwinyiwiwa, Bakari M. M.; Wolanski, Z.; Ooi, B. T.
    The pulse width modulation (PWM) technique has been proposed for the force-commutated shunt and series VAr controllers and unified power flow controllers in flexible AC transmission systems. The PWM converters can be operated as linear amplifiers of constant gain so that linear control system theory can be brought to bear more easily when applying feedback controls. For example, pole-placement and active filtering have been successfully applied in laboratory models. This paper is written as a tutorial describing the stages of signal processing: modulation, amplification and demodulation, without reference to power electronics since the solid-state switches are modelled as ON-OFF switches
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    Multimodular Multilevel Converters with Input/Output Linearity
    (IEEE Transactions on Industry Applications, 1997) Mwinyiwiwa, Bakari M. M.; Wolanski, Z.; Ooi, B. T.
    Multilevel converters constitute the key technology of power electronics to reach the high power ratings required by controllers of flexible AC transmission systems (FACTS). This paper shows that the sinusoidal pulsewidth modulation (SPWM) technique, as applied to multilevel converters, inherently requires a high switching rate. The paper then presents a strategy based on multiple modules of multilevel converters which operate with the lowest possible switching loss (each gate-turn-off thyristor (GTO) switches ON and OFF only once during the modulation period), while maintaining the high gain-bandwidth product of linear amplifiers to handle fast feedbacks, which FACTS controllers must be capable of, in order to carry out dynamic performance enhancement