بسم الله الرحمن الرحيم The Islamic University of Gaza Faculty of Engineering Electrical Engineering Department POWER ELECTRONICS EELE 5450— Summer 2012 Instructor: Eng. Jalal Al Roumy Lecture 9
Chapter Four Phase-Controlled Rectifiers (AC-DC) The thyristor switches allow forward current to be turned on at arbitrary times. But do not permit turn-off or commutation with out special turn-off circuitry. In normal AC-DC conversion the thyristor could be operated : 1- Natural commutation mode. ”when Vak < 0” (Easy to design) ( used in DC Motor drivers) 2- Forced commutation mode.
Chapter Four Basic controlled Rectifier circuits Assume that Peak supply voltage never exceeds the forward and reverse blocking rating.
Chapter Four Basic controlled Rectifier circuits 1- One voltage drop 2- Symmetrically PWM(SPWM) alpha=beta
Chapter Four Average Dc voltage value across resistance load
Chapter Four RMS voltage across resistance load
Chapter Four Average Dc voltage & RMS across resistance load
Chapter Four Half-Wave controlled rectifier with inductive load
Chapter Four Single Phase full-wave circuit (resistive load)
Chapter Four Single Phase full-wave circuit (resistive load) End of Lecture