Vaihtovirtajärjestelmien

Vaihtovirtajärjestelmä, often referred to as AC (Alternating Current) system, is an electrical system where the direction of electric current reverses periodically. This contrasts with direct current (DC) systems where the current flows in only one direction. The primary advantage of AC systems lies in their ability to be easily transformed to different voltage levels using transformers. This makes it efficient to transmit electricity over long distances at high voltages, reducing energy loss, and then step down the voltage to safer levels for use in homes and businesses.

The generation of AC typically occurs in alternators, which are electrical generators that produce alternating voltage and current. The voltage and current in an AC system vary sinusoidally with time. Key characteristics of an AC system include its frequency, which is the number of cycles per second (measured in Hertz, Hz), and its voltage, measured in volts. In most parts of the world, the standard frequency is 50 Hz or 60 Hz.

The widespread adoption of AC systems is largely due to the pioneering work of Nikola Tesla and George Westinghouse, who championed its advantages over DC systems for large-scale power distribution. AC is the standard for power grids worldwide, powering everything from household appliances to heavy industrial machinery.