文档介绍：Electric power system
An electric power system is work of ponents used to supply, transmit and use electric power. An example of an electric power system is work that supplies a region's homes and industry with power - for sizable regions, this power system is known as the gaid and can be broadly divided into the generators that supply the power, the transmission system that carries the power from the generating centres to the load centres and the distribution system that feeds the power to nearby homes and industries. Smaller power systems are also found in industry, hospitals, commercial buildings and homes. The majority of these systems rely upon three-phase AC power - the standard for large-scale power transmission and distribution across the modern world. Specialised power systems that do not always rely upon three-phase AC power are found in aircraft, electric rail systems, ocean liners and automobiles.
Basics of electric power
Electric power is the mathematical product of two quantities: current and voltage. These two quantities can vary with respect to time (AC power) or can be kept at constant levels (DC power).
Most refrigerators, air conditioners, pumps and industrial machinery use AC power where as puters and digital equipment use DC power (the digital devices you plug into the mains typically have an internal or external power adapter to convert from AC to DC p