電力系統(tǒng)中各種電壓的變電所及輸配電線路組成的整體，稱為電力網(wǎng)。它包含變電、輸電、配電三個單元。電力網(wǎng)的任務是輸送與分配電能，改變電壓。The overall system composed of various voltage substations and transmission and distribution lines in the power system is called the power grid. It consists of three units: power transformation, power transmission, and power distribution. The task of the power grid is to transmit and distribute electrical energy and change voltages.