Power Inverter

A power inverter is a power electronic device that converts direct current into alternating current, the reverse of the operation a rectifier performs, and unlike a generator it does not create power itself but reshapes power already supplied by a DC source such as a battery, a fuel cell or a solar array. Early DC to AC conversion relied on rotating machinery, motor generator sets and rotary converters, through the first half of the twentieth century; mercury arc valves took over large grid scale conversion from the 1950s through the 1970s, and the introduction of the silicon controlled rectifier in 1957 opened the way to today solid state inverters built from transistors and thyristors. A solar inverter is one of the critical balance of system components in a photovoltaic installation, tracking the panel array maximum power point and disconnecting automatically if the grid goes down, and grid tied inverters must keep the harmonic distortion of their output below 3 percent to meet standard grid interconnection rules. The largest inverters, built for high voltage direct current transmission systems, are rated at hundreds of megawatts, converting bulk DC power back to alternating current for distribution once it reaches its destination.