From Lecture1 vi , ii vo , io Power Processor Controller Source Load Islamic University of Gaza Faculty of Engineering Electrical Engineering Department From Lecture1 Power Processor Controller Load Measurement Reference POWER INPUT OUTPUT vi , ii vo , io Source Introduction to Power Electronics Lecture 2

Why do we need power converters? Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Converters Why do we need power converters? Power sources and loads come in various types of forms. We need a power converter to transfer the power from the source to the load while changing the form of the power. Introduction to Power Electronics Lecture 2

Islamic University of Gaza Faculty of Engineering Electrical Engineering Department The main task of power electronics is the conversion of one form of electrical energy to another. This process involves the conversion of voltage and current in terms of magnitude or RMS values, the change of frequency, and the number of phases. Power electronic components doing such conversions are referred to as converters. Introduction to Power Electronics Lecture 2

Converters are used in many different power and voltage ranges. Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Converters are used in many different power and voltage ranges. The spectrum of converting electrical power ranges from a few mW to several 100 MW. The voltage range extends from a few volts to several 10 kV or even 100 kV. Current ratings extends from mA to kA. Introduction to Power Electronics Lecture 2

Types of electric power Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Types of electric power AC Power DC Power Direct Current Alternative Current V DC Voltage Source/ Load t Introduction to Power Electronics Lecture 2

Types of electric power Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Types of electric power AC Power DC Power Direct Current Alternative Current AC wall power photovoltaic (PV) Introduction to Power Electronics Lecture 2

Four basic types of power converters Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Four basic types of power converters AC-DC AC Source --- DC Load Rectifier Examples: Laptop Charger Symbol: AC input DC output Introduction to Power Electronics Lecture 2

Four basic types of power converters Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Four basic types of power converters DC-DC DC Source --- DC Load Switching mode power supply (SMPS) Portable battery pack Symbol DC input DC output Introduction to Power Electronics Lecture 2

Four basic types of power converters Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Four basic types of power converters DC-AC DC Source --- AC Load Inverter PV-to-Grid System Symbol DC input AC output Introduction to Power Electronics Lecture 2

Four basic types of power converters Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Four basic types of power converters AC-AC AC Source --- AC Load AC Chopper: Common light-dimmer circuit. Wind Power System Symbol AC input AC output Introduction to Power Electronics Lecture 2

Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Introduction to Power Electronics Lecture 2

Important aspects in conversion of electrical energy Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Important aspects in conversion of electrical energy Costs. Life time and reliability. Quality of voltage and current (e.g. voltage accuracy (ripple content), harmonics of voltage and current, control dynamics etc.). Efficiency. Losses (losses are not only an issue of energy consumption, but also because of getting rid of the heat). Volume, weight (espy. for mobile applications). Introduction to Power Electronics Lecture 2

Some examples of applications of power electronic systems: Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Some examples of applications of power electronic systems: Power supplies for electronic home appliances, office, for telecommunication equipment and for personal computers or computer servers. Converters for motor drives to allow speed-variable operation of electrical drives (e.g. machine tools, conveyor drives, industrial drives, pumps and fans). Electrical wind turbines. Photovoltaic systems. Supplying a single-phase 16 2 3 Hz railway grid from 3-phase, 50 Hz national power grid. Supply of electric arc furnaces. Lightening control. Audio amplifiers. Introduction to Power Electronics Lecture 2

Converters & Applications of power electronics Islamic University of Gaza Faculty of Engineering Electrical Engineering Department Converters & Applications of power electronics Introduction to Power Electronics Lecture 2