Power Electronics in Smart Grid and Renewable Energy Systems [Scanning the Issue]

I am proudly presenting this special issue to the professional communities of the world. Power electronics is an extremely important element in modern smart grid and renewable energy systems. Basically, it uses high-efficiency switching power semiconductor devices to convert and control electrical power with the help of dc-to-dc, dc-to-ac, ac-to-dc, and ac-to-ac converters that are applied extensively in industrial, commercial, residential, transportation, aerospace, military, and utility systems. Power electronics plays significant role in modern industrial automation and high-efficiency energy systems that include renewable energy systems (such as wind and photovoltaic), bulk energy storage, electric and hybrid vehicles, and energy-efficiency improvement of electrical equipment. In modern electric power grid, power electronics is indispensable in high-voltage dc (HVDC) system, static VAR compensators (SVCs), flexible ac transmission system (FACTS)-based active and reactive power flow control, uninterruptible power system (UPS), fuel-cell-based energy system, etc. After a dynamic technology evolution for nearly five decades, power electronics has now grown possibly as the most important technology in the 21st century. Currently, most of our energy comes from fossil fuels and nuclear power plants. Fossil fuels cause environmental pollution that causes global warming or climate change problems. Nuclear energy is clean in that respect, but it has safety and radioactive waste disposal problems. For these reasons, the whole world is now turning toward renewable energy, where power electronics is an indispensable ingredient.