Tasavirtajärjestelmä

Tasavirtajärjestelmä, known in English as a direct current (DC) power system, is an electrical system where the electric charge flows in only one direction. Unlike alternating current (AC) systems, which are common in household electricity grids, the voltage and current in a DC system do not change direction over time.

DC power is generated by sources such as batteries, solar cells, and certain types of generators. It is also the form of electricity used by many electronic devices, including computers, smartphones, and LEDs. Historically, DC systems were the first to be developed for electricity distribution, but they faced challenges in transmitting power over long distances due to voltage drop.

Modern applications of DC systems are prevalent in various fields. High-voltage direct current (HVDC) transmission is used for efficiently transferring large amounts of electricity over very long distances, often under seas or across continents, as it incurs lower losses than AC for such applications. Electric vehicles also rely heavily on DC power for their batteries and motors. Furthermore, many renewable energy sources, like solar panels, produce DC power, which is then often converted to AC for grid integration or used directly to power DC appliances. The relative simplicity of DC circuits and the compatibility with electronic components make it a crucial aspect of modern electrical engineering.