In a normal alternating current power system, the voltage varies sinusoidally at a specific frequency, usually 50 or 60 hertz. When a linear electrical load is connected to the system, it draws a sinusoidal current at the same frequency as the voltage (though usually not in phase with the voltage).
When a non-linear load, such as a rectifier, is connected to the system, it draws a current that is not necessarily sinusoidal. The current waveform can become quite complex, depending on the type of load and its interaction with other components of the system.
This guide has been written for electrical Engineers who have to design, select electrical equipment, install these equipment and, inspect or maintain low-voltage electrical installations in compliance with international Standards of the International Electrotechnical Commission (IEC). “Which technical solution will guarantee that all relevant safety rules are met?” This question has been a permanent guideline for the elaboration of this document.
Basic DC-AC Converter Connections (Square-Wave Operation) • Control of the Output Voltage • Harmonics in the Output Voltage • Filtering of Output Voltage • Practical Realization of Basic Connections • Special Realizations (Application of Resonant Converter Techniques)
Budapest University of Technology and Economics
Polytechnic University, Brooklyn
Survey of Second-Order Resonant Circuits • Load Resonant Converters • Resonant Switch Converters • Resonant DC-Link Converters with ZVS
The term “ smart grid” defi nes a self - healing network equipped with dynamic optimization
techniques that use real - time measurements to minimize network losses, maintain
voltage levels, increase reliability, and improve asset management. The operational data
collected by the smart grid and its sub - systems will allow system operators to rapidly
identify the best strategy to secure against attacks, vulnerability, and so on, caused by
There is an upward trend that human activities involve more electric power nowadays
and for years to come. And we will soon be facing shortage of electricity supply if we
rely solely on non-renewable power generation from fossil fuels such as coals.
Renewable energy generation has proven effective in meeting the demand.
Stator current higher harmonics therefore have the same value regardless of the operating frequency. This is so due to the fact that DC voltage and hence rms values of all the voltage harmonics change proportionally to operating frequency.
Nowadays, the rapid growth of power electronics in industry and the presence of
products based on electronic components in enterprises, institutions, shops, small
businesses, residences, etc. and transport systems has been welcomed by the people
who already use it due to its increased productivity within all areas.
Power Quality Considerations
Harmonics • What Are Harmonics? • Harmonic Sequence • Where Do Harmonics Come From? • Effects of Harmonics on the System Voltage • Notching • Effects of Harmonics on Power System Components • Conductors • Three-Phase Neutral Conductors • Transformers • Effects of Harmonics on System Power Factor • Power Factor Correction Capacitors • IEEE Standard 519
Badrul H. Chowdhury
University of Missouri–Rolla
Tokyo Institute of Technology
Arizona State University
en the space limitations, the added material supplements, expands, and reinforces the ana-lytical methods that were, and continue to be, the main focus of this book. The analytical methods
are the foundation of electromagnetics and provide understanding and physical interpretation of
electromagnetic phenomena and interactions. Although numerical and computational methods
have, especially in the last four decades, played a key role in the solution of complex elec-tromagnetic problems, they are highly dependent on fundamental principles.