Islamic University of Gaza Faculty of Engineering Electrical

Islamic University of Gaza Faculty of Engineering Electrical Engineering Department THE FULL-BRIDGE CONVERTER Introduction

Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Introduction to Power Electronics

Islamic University of Gaza Faculty of Engineering Electrical Engineering Department 8. 3 THE SQUARE-WAVE

Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Ø The current waveform

Introduction to Power Electronics Dr. Moayed Almobaied Ch 8_2

Slides: 18

Download presentation

Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Inverters Converting dc to ac Ø Inverters are circuits that convert dc to ac. Ø More precisely, inverters transfer power from a dc source to an ac load. Ø The controlled full-wave bridge converters in Chap. 4 can function as inverters in some instances, but an ac source must preexist in those cases. Ø In other applications, the objective is to create an ac voltage when only a dc voltage source is available. Introduction to Power Electronics Dr. Moayed Almobaied Ch 8_2

Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Ø Inverters are used in applications such as adjustable-speed ac motor drives, uninterruptible power supplies (UPS), Ø and running ac appliances from an automobile battery. Introduction to Power Electronics Dr. Moayed Almobaied Ch 8_2

Islamic University of Gaza Faculty of Engineering Electrical Engineering Department THE FULL-BRIDGE CONVERTER Introduction to Power Electronics Dr. Moayed Almobaied Ch 8_2

Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Introduction to Power Electronics Dr. Moayed Almobaied Ch 8_2

Islamic University of Gaza Faculty of Engineering Electrical Engineering Department 8. 3 THE SQUARE-WAVE INVERTER Ø The simplest switching scheme for the full-bridge converter produces a square wave output voltage. Ø The switches connect the load to Vdc when S 1 and S 2 are closed or to -Vdc when S 3 and S 4 are closed. Ø The periodic switching of the load voltage between Vdc and -Vdc produces a square wave voltage across the load. Ø Although this alternating output is nonsinusoidal, it may be an adequate ac waveform for some applications. Introduction to Power Electronics Dr. Moayed Almobaied Ch 8_2

Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Ø The current waveform in the load depends on the load components. Ø For the resistive load, the current waveform matches the shape of the output voltage. Ø An inductive load will have a current that has more of a sinusoidal quality than the voltage because of the filtering property of the inductance. Ø An inductive load presents some considerations in designing the switches in the full-bridge circuit because the switch currents must be bidirectional. Introduction to Power Electronics Dr. Moayed Almobaied Ch 8_2

Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Introduction to Power Electronics Dr. Moayed Almobaied Ch 8_2